# Legality of incest

Laws regarding incest (i.e. sexual activity between family members or close relatives) vary considerably between jurisdictions, and depend on the type of sexual activity and the nature of the family relationship of the parties involved, as well as the age and sex of the parties. Besides legal prohibitions, at least some forms of incest are also socially taboo or frowned upon in most cultures around the world.
Incest laws may involve restrictions on marriage, which also vary between jurisdictions. When incest involves an adult and a child (under the age of consent) it is considered to be a form of child sexual abuse.

## Degrees of relationship

Laws regarding incest are sometimes expressed in terms of degrees of relationship. The degree of relationship is calculated by adding the number of generations back to a closest common ancestor of each individual. Consanguinity (but not affinity) relationships may be summarized as follows:
| Degree of relationship | Relationship | Average DNA shared % |
| | Inbred strain | 99% |
| 0 | identical twins; clones | 100% |
| 1 | parent-offspring | 50% |
| 1 | full siblings | 50% |
| 2 | 3/4-siblings or sibling-cousins | 37.5% |
| 2 | grandparent-grandchild | 25% |
| 2 | half-siblings | 25% |
| 3 | aunt/uncle-nephew/niece | 25% |
| 4 | double first cousins | 25% |
| 3 | great grandparent-great grandchild | 12.5% |
| 4 | first cousins | 12.5% |
| 6 | quadruple second cousins | 12.5% |
| 6 | triple second cousins | 9.38% |
| 4 | half-first cousins | 6.25% |
| 5 | first cousins once removed | 6.25% |
| 6 | double second cousins | 6.25% |
| 6 | second cousins | 3.13% |
| 8 | third cousins | 0.78% |
| 10 | fourth cousins | 0.20% |
Most laws regarding prohibited degree of kinship concern relations of r = 25% or higher, while most permit unions of individuals with r = 12.5% or lower. In 24 states of the United States, cousin marriages are prohibited. Also, most laws make no provision for the rare case of marriage between double first cousins. Incest laws may also include prohibitions of unions between biologically unrelated individuals if there is a close legal relationship, such as adoption or step relations.

## Table

| Country | Incest between consenting adults | Prohibited relationships | Penalties |
| Afghanistan | Illegal | Lineal ancestors and descendants Full and half-siblings | Death |
| Albania | Illegal | Lineal ancestors and descendants Full and half-siblings | Up to 7 years in prison |
| Algeria | Illegal | Relatives in the descending or ascending line Full, consanguineous or uterine brothers and sisters A person and the child of one of his full, consanguineous or uterine brothers or sisters or with a descendant thereof The mother or the father and the husband or the wife, the widower or the widow of his child or of another of his descendants Stepmother or stepfather and the descendant of the other spouse Persons one of whom is the wife or husband of a brother or sister | The penalty is ten (10) to twenty (20) years of imprisonment in the 1st and 2nd cases, five (5) years to ten (10) years of imprisonment in the 3rd, 4th and 5th cases and from two (2) years to five (5) years imprisonment in the 6th case |
| Angola | Legal | | |
| Antigua and Barbuda | Illegal | Parent, child brother, sister, grandparent, grandchild, uncle (by blood), niece, aunt (by blood) or nephew | For life, if committed by an adult with a person under fourteen years of age For fifteen years, if committed by an adult with a person fourteen years of age or more For two years, if committed between minors fourteen years of age or more |
| Argentina | Legal | | |
| Armenia | Illegal | | |
| Australia | Illegal | Varies by state | Varies by state (up to life imprisonment in one state: Queensland) |
| Austria | legal (for same-sex couples) / Illegal (for opposite-sex couples) | Lineal ancestors and descendants Full siblings and half siblings | Up to 3 years in prison or fine |
| Azerbaijan | Illegal | | |
| Bahamas | Illegal | Parent, child, brother, sister, grandparent, grandchild, uncle (by blood), niece, aunt (by blood) or nephew | If he is an adult who commits the offence with a minor, for life subject to, on a first conviction for the offence, a term of imprisonment of seven years, and in the case of a second or subsequent conviction for the offence, a term of imprisonment of fourteen years If he is an adult who commits the offence with another adult, for a term of ten years If he is a minor who commits the offence with another minor, for a term of two years |
| Bangladesh | Illegal | Lineal ancestors and descendants Full and half-siblings | Life imprisonment |
| Barbados | Illegal | Parent, child, brother, sister, grandparent, grandchild, uncle (by blood), niece, aunt (by blood) or nephew | If committed by an adult with a person under 14 years of age, for life If committed by an adult with a person 14 years of age or more, for 10 years If committed between minors 14 years of age or more, for 2 years |
| Belarus | Legal | | |
| Belgium | Legal | | |
| Belize | Illegal | Granddaughter, daughter, sister, half-sister, mother, grandfather, father, brother, half-brother or son | Imprisonment for seven years |
| Benin | Illegal | | |
| Bhutan | Illegal | A person to whom the defendant is related by consanguinity or affinity in such a way that they cannot legally marry | |
| Bolivia | Legal | | |
| Bosnia and Herzegovina | Illegal | | |
| Botswana | Legal | | |
| Brazil | Legal | | |
| Brunei | Illegal | Lineal ancestors and descendants Full and half-siblings | Death |
| Bulgaria | Illegal | Parent, grandparent, child, grandchild Brother, sister, half-brother, half-sister Uncle or aunt (by blood) Nephew or niece First cousin Grandaunt (by blood), granduncle (by blood), grandniece, grandnephew | Up to seven years in prison |
| Burkina Faso | Legal | | |
| Cabo Verde | Legal | | |
| Cambodia | Legal | | |
| Canada | Illegal | Child/parent or grandchild/grandparent Full and half-siblings | Up to 14 years in prison |
| Central African Republic | Legal | | |
| Chile | Illegal | Consanguineal ancestors and descendants Consanguineal siblings | From 61 days up to 3 years and 1 day in prison |
| China | Legal | | |
| Colombia | Illegal | Consanguineal and adopted ancestors and descendants Consanguineal and adopted siblings | From 16 up to 72 months in prison |
| Costa Rica | Legal | | |
| Croatia | Illegal | Linear ancestors and descendants Full and half-siblings | Up to one year in prison |
| Cuba | Illegal | | |
| Czech Republic | Illegal | Lineal ancestors and descendants Siblings Related by blood or adoption | Up to three years in prison |
| Democratic Republic of the Congo | Legal | | |
| Denmark | Illegal | Lineal ancestors and descendants Full siblings | Up to six years in prison (direct line) Up to two years in prison (siblings) |
| Dominica | Illegal | Parent and child Brother and sister, whether of the whole or the half blood, and whether the relationship is traced through lawful wedlock or not Uncle and niece or aunt and nephew Grandparent and grandchild | For twenty-five years, if committed by an adult with a person under fourteen years of age For ten years, if committed by an adult with a person fourteen years of age or more For two years, if committed between minors |
| Dominican Republic | Legal | | |
| East Timor | Legal | | |
| Ecuador | Legal | | |
| El Salvador | Legal | | |
| Eritrea | Illegal | Grandparent—grandchild or parent—child Brother or half brother, sister or half-sister Same-sex relations are always prohibited | From one to three years in prison |
| Estonia | Illegal (only incest between parent and child or grandparent and grandchild is illegal, incest between siblings is legal) | Grandparent—grandchild or parent—child | From two to eight years in prison |
| Eswatini | Illegal | Offspring, sibling, parent or grandparent | 25 years, if aged 14 years or less 20 years, if aged 14-18 years 10 years and E50.000, if 18 years or more 4 years and E20.000, if 18 years or more with consent |
| Ethiopia | Illegal | Blood relatives whose marriage is prohibited by respective law Same-sex relations are always prohibited | From three months to three years in prison |
| Federated States of Micronesia | Legal | | |
| Fiji | Illegal | "Carnal knowledge of" (sexual intercourse with) parent, grandparent or sibling. | Imprisonment for 20 years. |
| France | Legal | | |
| Gabon | Legal | | |
| Georgia | Illegal | Lineal ancestors and descendants Full and half-siblings | Up to two years in prison |
| Germany | Legal (for same-sex couples) / Illegal (for opposite-sex couples) | Lineal ancestors and descendants Full and half-siblings | Up to three years in prison or fine (not punished if both are minors) |
| Ghana | Illegal | Lineal ancestors and descendants Full and half-siblings | Prison sentence |
| Greece | Illegal | Lineal ancestors and descendants Full and half-siblings Uncle or aunt (by blood) Nephew or niece | More than 10 years in prison for the ascending relative if the descending relative is under 15 years old, imprisonment if 15 but not 18 years old, and up to two years in prison if 18 years and older Up to two years in prison if siblings or half-siblings or for the descending relative |
| Grenada | Illegal | Daughter/son, granddaughter/grandson, sister/brother, aunt/uncle (by blood) or niece/nephew | |
| Guatemala | Legal | | |
| Guinea-Bissau | Legal | | |
| Guyana | Legal (for opposite-sex couples) / Illegal (for same-sex couples) | | For same-sex couples: Life imprisonment |
| Haiti | Legal | | |
| Honduras | Legal | | |
| Hong Kong | Legal (for same-sex couples) / Illegal (for opposite-sex couples) | Granddaughter, daughter, sister or mother (male) Grandfather, father, brother or son (female) | Life imprisonment if under 13 20 years imprisonment if between 13 and 16 14 years imprisonment in other cases Consent of the Secretary of Justice is required for a prosecution |
| Hungary | Illegal | Lineal ancestors and descendants Sibling | Imprisonment not exceeding three years (for relatives in direct line) imprisonment not exceeding two years (for siblings) |
| Iceland | Illegal | Lineal ancestors and descendants Full and half-siblings | Up to eight years in prison for ascending relative Up to 12 years if descending relative is between 15 and 17 years old Up to four years in prison for siblings |
| India | Legal | | |
| Indonesia | Illegal | Lineal ancestors and descendants Full and half-siblings | Eight years imprisonment and 100 lashes |
| Ireland | Legal (same-sex couples) / Illegal (opposite-sex couples) | Granddaughter, daughter, mother, sister or half-sister (male) Grandfather, father, son, brother or half-brother (female) | Up to 10 years in prison (male and female) |
| Iran | Illegal | Lineal ancestors and descendants Full and half-siblings | Death |
| Israel | Legal (if aged 21 or older) / Illegal (if under the age of 21) | | |
| Italy | / Legal (unless it provokes public scandal) | | From two to eight years in prison |
| Ivory Coast | Legal | | |
| Jamaica | Legal (for opposite-sex couples) / Illegal (for same-sex couples) | | For same-sex couples: Ten years imprisonment with hard labour |
| Japan | Legal | | |
| Kazakhstan | Illegal | Close blood relatives | |
| Kenya | Illegal | "Indecent" acts or acts causing penetration with: daughter, granddaughter, sister, mother, niece, aunt or grandmother (if male) son, father, grandson, grand father, brother, nephew or uncle (if female). | Imprisonment for a term of not less than ten years. |
| Kiribati | Illegal | Sexual intercourse with: granddaughter, daughter, sister or mother (if male) grandfather, father, brother or son (if female from the age of 15) | Imprisonment for 7 years. |
| Kosovo | Legal | | |
| Kyrgyzstan | Legal | | |
| Laos | Illegal | Biological parent, parent by adoption, step-parent, grandparent, parent in law, biological child, adopted child, step-child, grandchild or sibling | Six months to five years of imprisonment and a fine from 500,000 Kip to 2,000,000 Kip Three months to one year of imprisonment and a fine from 50,000 Kip to 300,000 Kip (for partners) |
| Latvia | Legal | | |
| Lesotho | Legal | | |
| Liberia | Illegal | Lineal ancestors and descendants Full and half-siblings | Up to three years in prison |
| Liechtenstein | Illegal | Lineal ancestors and descendants Full siblings and half siblings | Up to 3 years in prison or fine |
| Lithuania | Legal | | |
| Luxembourg | Legal (1810–1941 and since 1944/45 (1942–1944/45 illegal pursuant to § 173 German penal code) | | |
| Macau | Legal | | |
| Madagascar | Legal | | |
| Malaysia | Illegal | Relatives prohibited by religious law | From six to 20 years in prison Flagellation |
| Malawi | Illegal | "Carnal knowledge of" (sexual intercourse with): grand-daughter, daughter, sister, mother or grandmother (if male) grandfather, father, brother, or son (if female from the age of 16). | Imprisonment for five years. |
| Mali | Legal | | |
| Marshall Islands | Illegal | Marriage, cohabitation or sexual intercourse with another of such a close blood relationship or affinity that marriage between the two who so engage is prohibited by custom. | Classified as felony of the third degree, which is punishable by a fine of $5,000 or imprisonment for no more than thirty-five months. |
| Mauritius | Illegal | Lineal ancestors and descendants Full and half-siblings | Imprisonment |
| Mexico | Illegal | Varies by state | Varies by state |
| Moldova | Illegal | Relatives in the direct line up to and including the third degree of kinship, as well as between relatives in the collateral line (brothers and sisters) | Imprisonment for up to 5 years Not subject to criminal liability if under 18 years of age and the age difference between them does not exceed 2 years |
| Mongolia | Legal | | |
| Montenegro | Legal | | |
| Mozambique | Legal | | |
| Myanmar | Illegal | | |
| Nauru | Illegal | Lineal ancestors and descendants Full and half-siblings | 10 years imprisonment, |
| Nepal | Illegal | Lineal ancestors and descendants Collateral relatives within (including) 7 degrees | Imprisonment for life for sexual intercourse between the natural mother and her natural son or between the natural father and his natural daughter Imprisonment for four to ten years and a fine of रु (rupees) 40,000–100,000 for sexual intercourse between: stepmother and stepson stepfather and stepdaughter full blood brother and sister father-in-law and daughter-in-law within the same branch grandfather and granddaughter or great-granddaughter within the same branch brother-in-law and sister-in-law within the same branch Imprisonment for three to six years and a fine of रु 30,000–60,000 for sexual intercourse between: grandmother and her grandson or great-grandson within the three generations of the same branch father's elder brother or uncle and niece within the same branch aunt (including the wife of own father's brother) within the same branch father-in-law and brother's daughter-in-law within the same branch uterine maternal uncle and niece or nephew and maternal aunt mother's sister and nephew or between mother-in-law (one's wife side) and son-in-law Imprisonment for one to three years and a fine of रु 10,000–30,000, having regard to, inter alia, the branch, relationship and generation, for sexual intercourse between persons in collateral relatives within (including) 7 degrees, except that referred to in clause (a), (b) or (c) |
| Netherlands | Legal | | |
| New Zealand | Illegal | Lineal ancestors and descendants Full or half-siblings | Up to 10 years in prison |
| Nicaragua | Legal | | |
| Niger | Legal | | |
| Nigeria | Illegal | Lineal ancestors and descendants Full and half-siblings | Death |
| North Korea | Illegal | Lineal ancestors and descendants Collateral relatives within (including) 4 degrees | Death |
| North Macedonia | Illegal | Linear ancestors and descendants Full and half-siblings | Up to three years in prison |
| Northern Cyprus | Illegal | Child, grandchild, sibling, adopted child or child of his/her sibling who is below the age of 18 Grandchildren, child, mother, father, grandfather, grandmother, aunt, uncle, maternal uncle or aunt who is more than 18 and aware of the familial relation between the two Sibling, step-sibling, adopted sibling who is also between 16 and 18 | Life imprisonment Up to six months imprisonment or a fine |
| Norway | Illegal | Lineal ancestors and descendants Siblings Stepfamily Adopted descendants | Up to six years in prison |
| Pakistan | Illegal | Lineal ancestors and descendants Full and half-siblings | Death |
| Palau | Illegal | Within the degrees of consanguinity or affinity within which marriage is prohibited by law or custom | Imprisonment for a period of not more than twenty-five years, or fined up to fifty thousand dollars ($50,000), or both |
| Panama | Legal | | |
| Paraguay | Legal | | |
| Peru | Legal | | |
| Philippines | Legal | | |
| Poland | Illegal | Lineal ancestors and descendants Adopted children and parents Full and half-siblings | From three months to five years in prison |
| Portugal | Legal | | |
| Qatar | Illegal | Lineal ancestors and descendants Full and half-siblings | Death |
| Republic of the Congo | Legal | | |
| Romania | Illegal | Parent, grandparent, child, grandchild Brother, sister, half-brother, half-sister Uncle or aunt (by blood) Nephew or niece First cousin Grandaunt (by blood), granduncle (by blood), grandniece, grandnephew | Between one and five years of imprisonment |
| Russia | Legal | | |
| Samoa | Legal (if aged 21 or older) / Illegal (if under the age of 21) | parent and child, siblings, half-siblings, or grandparent and grandchild "child" includes an illegitimate child or an adopted child; and "grandchild" has a corresponding meaning | Imprisonment for a term not exceeding 14 years |
| Saudi Arabia | Illegal | Lineal ancestors and descendants Full and half-siblings | Death |
| Saint Kitts and Nevis | Legal | | |
| Saint Lucia | Legal (for opposite-sex couples) / Illegal (for same-sex couples) | | For same-sex couples: Ten years of imprisonment |
| Saint Vincent and the Grenadines | Legal (for opposite-sex couples) / Illegal (for same-sex couples) | | For same-sex couples: Ten years of imprisonment |
| Senegal | Illegal | Lineal ancestors and descendants Full and half-siblings | Up to three years in prison |
| Serbia | Legal | | |
| Seychelles | Illegal | Grandfather, father, brother, half-brother, son or grandson grandmother, mother, sister, half-sister, daughter or grand-daughter | Imprisonment for 3 years |
| Sierra Leone | Illegal | Brother, half-brother, nephew, father, son or grandfather Sister, half-sister, mother, grandmother, daughter or niece | Imprisonment for a term not less than five years and not exceeding fifteen years |
| Singapore | Illegal | Lineal ancestors and descendants Full and half-siblings Uncle (by blood), aunt (by blood), nephew, niece | Up to ten years in prison |
| Slovenia | Legal | | |
| South Africa | Illegal | Ascendants and descendants in the direct line Collaterals, if either of them is related to their common ancestor in the first degree of descent | |
| South Korea | Legal | | |
| Somalia | Illegal | Lineal ancestors and descendants Full and half-siblings | Death |
| South Sudan | Illegal | Lineal ancestors and descendants Half or full sibling, uncle (by blood), aunt (by blood), niece, nephew Same-sex relations are always prohibited | Up to seven years in prison Fine |
| Spain | Legal | | |
| Sri Lanka | Illegal | Directly descend from the other, adoptive parent, adoptive grand parent, adopted child or adopted grand child Sister, either by the full or the half blood or by adoption, daughter of his brother or of his sister, by the full or the half blood or by adoption, a descendant from either of them, the daughter of his wife by another father, his son's or grandson's or father's or grandfather's widow Brother of the female either by the full or the half blood or by adoption, the son of her brother or sister by the full or the half blood or by adoption, a descendant from either of them, the son of her husband by another mother, her deceased daughter's or grand daughter's or mother's or grand mother's husband | Imprisonment for a term not less than seven years and not exceeding twenty years and with fine Imprisonment for a terms which may extend to two years (if attempted) |
| Sweden | Illegal | Vaginal intercourse illegal for the ancestor, imprisonment up to 2 years Vaginal intercourse illegal for full siblings, imprisonment up to 1 year | |
| Switzerland | legal (for same-sex couples) / Illegal (for opposite-sex couples) | Lineal ancestors and descendants Full siblings and half siblings | Up to three years in prison or fine |
| Sudan | Illegal | Lineal ancestors and descendants or their spouses Sister, brother or their children, aunt (by blood) or uncle (by blood) Same-sex relations are always prohibited | Death if relations are same-sex; Additional punishment of up to five years in prison otherwise |
| Suriname | Legal | | |
| Syria | Illegal | Parents and offspring, brothers and sister, step-brother and step-sister, or those of the same category among in-laws | One to three years imprisonment If one of the offenders has legal or actual authority over the victim, the penalty shall not be less than two years, and the offender is denied the right of guardianship. |
| Taiwan | Illegal | Lineal ancestors and descendants. Collateral relatives within (including) 3 degrees. | Up to five years imprisonment, but prosecution cannot start without a complaint by the victim within six months of them being aware of the identity of the offender (Antragsdelikt). |
| Tajikistan | Legal | | |
| Tanzania | Illegal | Granddaughter, daughter, sister or mother (male) Grandfather, father, brother or son (female) Same-sex relations are always prohibited | Up to five years in prison |
| Thailand | Legal | | |
| Timor-Leste | Legal | | |
| Togo | Illegal | Lineal ancestors and descendants Full and half-siblings | Prison sentence |
| Trinidad and Tobago | Illegal | Parent, child, brother, sister, grandparent, grandchild, uncle (by blood), niece, aunt (by blood) or nephew | Imprisonment for life |
| Tunisia | Illegal | The rape of a child that is carried out by: Brothers and sisters The son of any of his or her brothers or sisters Any of their descendants The husband's father or the wife's father or the mother's husband or the father's wife or the husband's family Persons who are spouses of a brother or sister | Twelve years imprisonment (six years for indecent assault, doubled if the perpetrator is a family member or relative of the victim) |
| Turkey | Legal | | |
| Turkmenistan | Illegal | Lineal ancestors and descendants Full and half-siblings | Prison sentence |
| Uganda | Illegal | Lineal ancestors and descendants Full and half-siblings | Life imprisonment |
| Ukraine | Legal | | |
| United Arab Emirates | Illegal | Lineal ancestors and descendants Full and half-siblings | Death |
| United Kingdom | Illegal | Parent, grandparent, child, grandchild Brother, sister, half-brother, half-sister Uncle or aunt (by blood) Nephew or niece | Up to two years imprisonment for sex between adult relatives (penetration) Up to 14 years imprisonment for sexual activity with a child family member |
| United States | legal (only 2 states: Rhode Island and New Jersey) / Illegal (other 48 states, but in Ohio, only incest between parent and child or grandparent and grandchild is illegal, incest between siblings is legal) | Varies by states | Varies by states (up to life imprisonment in four states: Idaho, Kentucky, Montana, Nevada) |
| Uruguay | / Legal (unless it provokes public scandal) | | |
| Uzbekistan | Illegal | Lineal ancestors and descendants Full and half-siblings | Prison sentence |
| Vanuatu | Illegal | Starting from the age of 16 for both sexes, sexual intercourse between: parent and child (including an adopted child); brother and sister (including half blood); grandparent and grandchild. | Imprisonment for 10 years. |
| Venezuela | / Legal (unless it provokes public scandal) | | |
| Vietnam | Illegal | Lineal ancestors and descendants Sibling or half-sibling | From one to five years in prison |
| Zambia | Illegal | Granddaughter, daughter, sister, mother (male) Grandfather, father, brother, son (female) Same-sex relations are always prohibited | Up to five years in prison |
| Zimbabwe | Illegal | Lineal ancestors and descendants Collateral relatives within (including) 6 degrees | Up to five years in prison, or fine up to US$5000, or both |

## Countries in Africa that criminalize incest
### Zimbabwe

In Zimbabwe, most forms of incest are illegal and an offender is currently liable to a fine up to or exceeding level fourteen (about US$5000) or imprisonment for a period not exceeding five years or both. Incest is classified as "sexual intercourse within a prohibited degree of relationship". A prohibited degree of relationship would be that of a parent and their natural or adoptive child, a step-parent and their step-child, whether the step-child's parent and step-parent are married under the Marriage Act [Chapter 5:11] or the Customary Marriages Act [Chapter 5:07], or are parties to an unregistered customary law marriage, and whether or not the child was over the age of eighteen years at the time of the marriage; a brother and sister, whether of whole or half blood; or an uncle and his niece; or a grand-uncle and his grand-niece; or an aunt and her nephew; or a grand-aunt and her grand-nephew; or a grandparent and their grandchild and any person and their first or second cousin. In cases of first and second cousins an individual charged with such a crime can raise a defense that the cultural or religious customs or traditions of the community to which they belong does not prohibit marriage between first or second cousins; or in the case of a person who is a member of a community governed by customary law, that the cultural or religious customs or traditions of the particular community to which they belong does not prohibit marriage between first or second cousins.

## Countries in the Americas that criminalize incest
### Canada

Under Canadian federal law, incest is defined as having a sexual relationship with a sibling (including half-sibling), child/parent or grandchild/grandparent, requiring knowledge of the existence of the blood relationship. Everyone who commits incest is guilty of an indictable offence and is liable to imprisonment for a term of not more than 14 years and, if the other person is under the age of 16 years, to a minimum punishment of imprisonment for a term of five years.

### United States

Laws regarding incest in the United States vary widely among jurisdictions regarding both the definition of the offense and penalties for its commission. The laws regarding incest in the United States article summarizes these laws for individual U.S. states and the District of Columbia.
In the United States, the District of Columbia and every state and inhabited territory have some form of codified incest prohibition. In most states, sexual activity between a lineal ancestor and a lineal descendant (parent, grandparent with child or grandchild), siblings (brother-sister) and aunt-nephew, uncle-niece is penalized as incest. However, individual statutes vary widely. Rhode Island has repealed its criminal incest statute, and only criminalizes incestuous marriage. Ohio "targets only parental figures", and New Jersey penalize it either as aggravated sexual assault when both parties are under 16 years of age, as sexual assault over 16 years of age but under 18, or as "sexual conduct which would impair or debauch the morals of the child" in the case of a parent or another adult having legal care of a child under 18 years of age. The most severe penalties for incest are in Massachusetts, Virginia, Texas and Oregon, which punish incest with up to 20 years in prison, Georgia where a penalty for incest is up to 30 years in prison, Wisconsin where the penalty for incest is up to 40 years in prison, and in the states of Colorado, Nevada, Montana, Idaho and Michigan where a penalty of up to life imprisonment for incest may be given.
In some states, sex between first cousins is prohibited (see cousin marriage law in the United States by state for cousin sex, as well as cousin marriage, being outlawed in some states). Many states also apply incest laws to non-blood relations, including stepparents, stepsiblings, in-laws and people related through adoption.

## Countries in Asia that criminalize incest
### Hong Kong

In Hong Kong, a special administrative region of China, it is illegal to have sexual intercourse with certain close relatives, even if they are consenting adults. The prohibited relationships are grandfather-granddaughter, father-daughter, brother-sister and mother-son. Punishment is up to 20 years' imprisonment for male offenders and up to 14 years' imprisonment for female offenders. The law does not cover sexual intercourse with more distant relatives, such as an aunt, uncle, niece, nephew and cousin. It only addresses male-on-female and female-on-male sexual intercourse, and it appears that consensual same-sex incest is not illegal. The law makes an assumption that a female below the age of 16 has no ability to consent to sexual intercourse, therefore a female below 16 cannot commit incest.
On 5 December 2019, the Law Reform Commission of Hong Kong ("LRC") published a report on Review of Substantive Sexual Offences making final recommendations for the reform of substantive sexual offences in the Crimes Ordinance (Cap 200). It recommended that "the offence of incest should be reformed to become gender neutral; to cover all penile penetration of the mouth, vagina and anus and other forms of penetration; and be extended to cover uncles (aunts) and nieces (nephews) who are blood relatives as well as adoptive parents".

### Malaysia

In Malaysia, it is illegal to have sexual intercourse with a person who under the law, religion, custom or usage that applies to the person he or she is not permitted to marry on account of their relationship.
In addition to whipping, persons convicted of incest face a minimum sentence of six years' imprisonment and a maximum sentence of 20 years' imprisonment. It is a defense against the charge if the person did not know the relationship was not permitted or if the sexual intercourse was done without his or her consent. Girls below the age of 16 and boys below the age of 13 are deemed to be incapable of giving consent. (The age of consent for sex in Malaysia is 16 for both sexes.)
While it is unclear to which family members the incest law applies, a verdict from the High Court in Sabah and Sarawak in 2011 provided some indication about the sentencing guidelines. It described incest as a "heinous crime" but that the degree of kinship between the parties dictates the "level of repulsion" which the court translates into a sentence imposed. The verdict said the worst on such a scale is incest committed by a father to his biological daughter or a brother to his biological sister, and that such offenders should receive the harshest sentence. It said an uncle and his maternal niece committing incest is not on that same level and, if there was no violence involved, the length of the sentence should reflect it.
There are more severe sentences for those who commit incest through rape. The offence of incestuous rape is punishable with not less than eight years' imprisonment and not more than 30 years' imprisonment. In addition, those convicted receive not less than 10 strokes.
Malaysian law also considers sexual intercourse with the stepfamily to be incestuous.

### Pakistan

The legal code of Pakistan defines incest as marriage (consortion) between a male and either his:
* Wife or former wife of father, grandfather and further ancestors
* Mother, grandmother and further ancestors
* Daughter, granddaughter and further descendants
* Full or half-sister
* Parents' sisters, grandparents' sisters and further ancestors' sisters
* Daughter, granddaughter and further descendant of full or half-sibling
* Suckling ancestor
* Suckling sister
* Mother, grandmother and further ancestors of wife or former wife
* Daughter, granddaughter of wife or former wife
* Wife or former wife of true son or grandson and further descendants
* Sororal polygyny
* Close relations or blood relations

## Countries in Europe that criminalize incest

Countries that prohibit incest include: (all articles refer to the Penal Codes) Germany Article 173, Albania Article 106, Slovenia Article 195, Slovakia Section 203, Serbia Article 197, Poland Article 201, Norway Article 197 and 198, Hungary Article 199, Bulgaria Article 154, and Cyprus Article 147.
Countries that allow consensual incest if both are over 18 include Belarus, Belgium, Estonia, Latvia, Lithuania, France, Russia, Spain, Ukraine, and Portugal. Russia and Belarus also allow incest between teenagers (under 18). Estonia, Latvia, and Ukraine prohibit incest if one has custody over the other.

### Austria

In Austria, incest between lineal ancestors and descendants and between full siblings is prohibited. It is punishable by up to three years in prison.

### Belarus

There is no law specifically criminalising incest in Belarus.
Section 168 of the criminal code, does however prohibit all forms of sexual activity (including incest) with anyone aged under 16 (the age of consent in Belarus).

### Czech Republic

Section 188 of the Czech Criminal code prohibits incest between lineal ancestors and descendants and siblings. The maximum penalty is three years of imprisonment.

### Denmark

In Denmark, incest is sex between lineal ancestors and descendants and between full siblings. Sex with a descendant is punishable by up to six years imprisonment. Sex between siblings is punishable by up to two years imprisonment.

### Estonia

In Estonia, sexual intercourse or commission of another act of sexual nature by a parent, person holding parental rights or grandparent with a child or grandchild is punishable by two to eight years imprisonment.

### Finland

In Finland, sexual acts between one's full sibling (but not half-sibling), ancestor or descendant are punishable by a fine or up to two years in prison for "sexual act between close relatives". However, no punishment is given to a person who was under 18 years old when performing a sexual act with a parent or grandparent or if the person was forced or illegally persuaded to perform the sexual act. The marriage law defines, that marriage between one's sibling, half-sibling, ancestor or descendant is forbidden.

### France, Belgium, and Luxembourg

The French Penal Code of 1810, which was promulgated by Napoleon I, and became the criminal law in many of the territories occupied at the time by the First French Empire, abolished incest laws in France, Belgium, and Luxembourg.
In 2010, France reinstated laws against incest by introducing article 222-31-1 of the penal code. From February 10, 2010, to September 17, 2011, rape and sexual assault were classified as incest when they are committed "within the family on a minor by an ascendant, a brother, a sister or any other person, including a cohabitant of a family member, who has de jure or de facto authority over the victim".
There were subsequently multiple changes to the definition of incest.
On 16 September 2011, the Constitutional Council repealed article 222-31-1 of the penal code, saying that if it was possible for the legislator to institute a particular penal qualification to designate incestuous sexual acts, they could not, without disregarding the principle of legality of offences and penalties, refrain from precisely designating the persons who must be considered, within the meaning of this qualification, as members of the family.
Incest was once again reinstated in 2016. From March 16, 2016, to August 6, 2018, rape and sexual assault are considered incestuous when they are committed on a minor by:
* An ancestor;
* A brother, sister, uncle, aunt, nephew or niece;
* The spouse or partner of one of the persons mentioned in (1) and (2) or the partner bound by a civil solidarity pact with one of the persons mentioned in 1 and 2, if he or she has de jure or de facto authority over the minor.
On 6 August 2018, "if he or she has de jure or de facto authority over the minor" in (3) was changed to "if he or she has de jure or de facto authority over the victim".

### Germany

In Germany, illegal incest is defined as vaginal intercourse between lineal ancestors and descendants (parents, grandparents, great-grandparents and their children, grandchildren, great-grandchildren) and between full and half-siblings (due to this definition other sexual practices, including homosexual intercourse, are not punishable). The penalty is a fine or up to three years of prison. Incest between relatives who are minors (below 18 years old) at the time of offence is not punishable but remains a crime, therefore aiding and abetting of incest between related minors is punishable.
Regarding marriage, the same rules apply and prohibit marriage between aforementioned relatives, but also includes marriages between siblings by adoption.
The criminal liability of incest among consenting adults is disputed among German citizens and politicians. In the case of Patrick Stübing, the Federal Constitutional Court ruled in 2008 that the criminalization of incest is constitutional in a 7:1 vote with one judge dissenting.
In September 2014 the majority of the German Ethics Council recommended that the government abolish laws criminalizing consensual incest between adult siblings, while not broaching the question of to what extent criminal liability for incest between parents and children of legal age might be abrogated. A minority of nine members of the Council dissented, opposing a repeal of Section 173 of the Criminal Code

### Greece

Article 345 of the Greek Penal Code as modified by Article 2, Paragraph 8 of Law 3625/2007 and Article 3 Paragraph 10 of Law 3727/2008 prohibits incestuous relations between relatives of both ascending and descending line, and between half or full siblings, and imposes (1) for the ascending relative (for example father, uncle, grandfather etc.): at least 10 years' imprisonment if the descending relative is under 15 years old, imprisonment if 15 but not 18 years old, and maximum two years' imprisonment if 18 years and older; (2) for the descending relative (for example child, nephew etc.) maximum two years' imprisonment; (3) for half- or full siblings maximum two years' imprisonment. Paragraph 2 of Article 345 Penal Code also states that if the descending relative and the half or full siblings were under 18 years old, they might be cleared of any charge.
Also, Article 1357 of the Greek Civil Code prohibits the marriage of relatives of direct blood line in totality, and up the four degrees of consanguinity of the secondary blood line (for example you can marry the first cousin of your mother / father, but not your first cousin), also the marriage of relatives five or six degrees of consanguinity is under permission only. Article 1358 of the Greek Civil Code also prohibits the marriage of relatives in law totally in direct blood line, and up the third degree of the secondary blood line.

### Iceland

Article 200 of the Icelandic Penal Code prohibits incestuous relations between relatives of both ascending and descending line, and between half or full siblings, and (1) imposes for the ascending relative (for example father, uncle, grandfather etc.): imprisonment up to a maximum of 12 years if the descending relative is between 15 and 17 years old, imprisonment up to a maximum of eight years if 18 years and older; (2) for siblings a maximum four years' imprisonment—if the half or full siblings were under 18 years old, they might be cleared of any charge.

### Ireland

Incest is illegal in the Republic of Ireland under the Punishment of Incest Act 1908, which pre-dates the foundation of the state.
It is illegal for a male to have sexual intercourse with his granddaughter, mother, daughter, sister, or half-sister; and for a female (over 16 years of age) with her grandfather, father, son, brother, or half-brother. The act does not refer to other familial relationships (such as grandson-grandmother), or same-sex relations.
Prior to the amendment of the 1908 Act in 2019, incest was punishable by up to seven years' imprisonment for a female and up to life imprisonment for a male. The Criminal Law (Sexual Offences) (Amendment) Act 2019 amended the Act of 1908 to provide for a maximum term of 10 years' imprisonment for both males and females.
Occasionally, offenders convicted of incest will be admitted to a psychiatric hospital for psychiatric treatment.

### Italy

Incest is illegal in Italy only if it provokes public scandal, according to Article 564 of the Penal Code and punishable from two to eight years' imprisonment, open to more years for the older person if the other was under aged. For incest to be a "public scandal" the incest must be done in a blatant manner. The fact that someone reports incest to the authorities does not by itself make it a public scandal.

### Latvia

Incest is not criminally prohibited in Latvia except as part of the general protection of adolescents from sexual abuse.

### Lithuania

Criminal Code of Lithuania does not explicitly foresee a criminal punishment for incest between adults. However, it does state that "A father, mother, guardian, custodian or another lawful representative of a child or a person holding statutory powers in respect of a minor who has sexual intercourse or otherwise satisfied his sexual desires with that minor, in the absence of characteristics of a rape, sexual assault or sexual abuse, shall be punished by a fine or by restriction of liberty or by arrest or by a custodial sentence for a term of up to six years." Thereby, the law explicitly foresees a criminal punishment for incest between a parent and a child or for persons of similar standing.

### Netherlands

Consensual incest between adults is legal in the Netherlands. Marriage is forbidden between ancestors and descendants or between siblings, although the Minister of Justice may grant dispensation in the case of siblings by adoption. Marriage between blood relations of the third and fourth degree are possible, but require both partners to sign a declaration of consent (Dutch civil law book 1, articles 41 and 41a).

### Norway

Incest is illegal in Norway and is defined as intercourse between ancestors and descendants (including adopted descendants), siblings, and even stepfamily. It is punishable by up to six years in prison.

### Poland

In Poland, incest is defined in Article 201 of the Penal Code as sexual intercourse with an ancestor, descendant, guardian, ward, brother, or sister, and is punishable by imprisonment for no less than three months and no more than five years.

### Portugal

In Portugal, incest between consenting adults was decriminalized in 1983, and has remained legal since then.

### Romania

Incest is defined in the Penal Code as "consensual sexual relations between lineal relatives or between siblings" and is punished by a year to five years in prison.

### Russia

In Russia, sexual activity (including incest) between persons who are over the age of consent (16 in Russia) is not a criminal offence.
However, under the Family Code of Russia, persons who are related lineally, siblings, half-siblings, and a stepparent and a stepchild may not marry.

### Serbia

Incest between consenting adults has been decriminalized in Serbia since the adoption of the 2005 Penal Code. Article 197 of the Penal Code prohibits only incest between an adult and a minor relative and between an adult and a minor sibling. Amendments in 2009 increased the penalty from the previous three year prison sentence to a term between 6 months minimum and a 5 year maximum prison sentence.

### Slovenia

Incest in Slovenia is not criminally prohibited unless one person is a minor. A person who has sexual relations with a blood relation minor is punished to two years in prison.

### Spain

Consensual incest is legal in Spain since there is no law against it. However, both parties must be over the age of consent in Spain (16) to have sex.

### Sweden

Vaginal intercourse with a descendant or a full sibling is prohibited by law in Sweden. Other kinds of sexual activity, including same-sex activity, are not directly penalized. Half-siblings can engage in sexual intercourse and even marry, but require special approval by the government.

### Switzerland

Article 213 of the Swiss Criminal Code prohibits incest. Intercourse among siblings or other persons related by blood in direct line is punishable by up to three years' imprisonment. The federal government proposed to abolish this prohibition in 2010, arguing that in the few cases where persons were convicted of incest (three since 1984), other sexual crimes such as child sexual abuse were also committed.

### Ukraine

There appears to be no law prohibiting incest but there is a law restricting it. Article 155 of the criminal code prohibits penetrative sex with anyone under 16. The same article also prohibits incest with a person under 16 with whom one has custodial authority (such as father-minor-daughter).

### United Kingdom

The United Kingdom is a political union of four different countries (England and Wales, Scotland and Northern Ireland), therefore legislation regarding sexual offences in the United Kingdom is devolved. However in each UK nation the relevant legislatures have enacted legislation prohibiting incest, regardless of age, or perceived consent.
England and Wales
Incest is illegal in England and Wales under the Sexual Offences Act 2003.
Prohibited degrees of kinship (what constitutes incest) are defined as relationships which involve a person (A) being related to person (B) as either: a parent, grandparent, child, grandchild, brother, sister, half-brother, half-sister, uncle, aunt, nephew or niece.
The act also goes on to include adoptive parents, and their children under the terms of the act, meaning that sexual relations between adoptive parents and their children are still illegal in England and Wales even once their children reach or are over the age of consent.
The act provides distinction between familial child sex offences (sections 25–29) and sex which occurs between adult relatives (sections 64–65). The former holding a higher sentence than the latter.
Northern Ireland
As is the case in the Republic of Ireland, incest is also illegal in Northern Ireland, as per the Sexual Offences (Northern Ireland) Order 2008.
Scotland
In Scotland the offence is against the Criminal Law (Consolidation) (Scotland) Act 1995, the provisions of which effectively replaced the Incest and Related Offences (Scotland) Act 1986 (although the 1986 Act was not actually repealed until 2010). Prior to the 1986 Act the law was based on the Incest Act 1567 which incorporated into Scots criminal law Chapter 18 of the Book of Leviticus, using the version of the text of the Geneva Bible of 1562. In January 2016 a petition calling for "Adult Consensual Incest" to be decriminalised was submitted to the Scottish Parliament's Public Petitions Committee, but the petition was not debated and no change was made to the law. In August 2016 and December 2017, further petitions were submitted to the Scottish Parliament's Public Petitions Committee.

## Countries in Oceania that criminalize incest
### Australia

In Australia, federal marriage law prohibits marriage between an ancestor and descendant or siblings (including a sibling of half-blood), including those traced through adoption. However, under federal law, sexual conduct between consenting adults (18 years of age or older) is legal, which also applies to close family members. but what constitutes incest and penalties vary.
In all Australian states and territories except New South Wales, sexual intercourse between a lineal ancestor and a lineal descendant is incest. In New South Wales, incest involves "close family members", which are "parent, son, daughter, sibling (including a half-brother or half-sister), grandparent or grandchild, being such a family member from birth". In Queensland, unlawful incest also includes sexual intercourse between an uncle or aunt with their niece or nephew, although here its application is curtailed by the effect of the federal Marriage Act 1961, as the Queensland Criminal Code states that the crime of incest does not apply to "persons who are lawfully married or entitled to be lawfully married". Thus, it is not incest for a niece aged 16 or over to engage in sexual intercourse with her uncle or aunt, or a nephew aged 16 or over to engage in sexual intercourse with his aunt or uncle (the Marriage Act allows same-sex marriage).
In New South Wales, incest is generally only applied in cases where both participants are aged 16 or over (the age of consent in the state). Where a participant is aged between 10 and 16 years of age, the older participant would generally be charged with sexual intercourse with a child under the age of 16, while in cases when a participant is under 10, the older participant would generally be charged with sexual intercourse with a child under the age of 10. In the other states and territories, incest can also arise where one of the parties is below the age of consent, but this does not exclude the possibility of bringing the more general charge of sexual intercourse with a child under the age of 10 (New South Wales and Northern Territory), 12, 13 (Western Australia), 14 (South Australia), 16 or 17 (South Australia and Tasmania) as the case may be. This is particularly relevant where a certain form of sexual conduct between related persons falls outside of the legal definition of incest in a particular jurisdiction.
In no state or territory is consent a defense to incest. The maximum penalty for incest varies: eight years' imprisonment in New South Wales; 10 years' imprisonment in South Australia; 20 years' imprisonment in Western Australia and the Australian Capital Territory; 25 years' imprisonment in the Northern Territory, Victoria, and Tasmania; and life imprisonment in Queensland.
In regards to sex offender registration, any person convicted of incest is required to register as a sex offender seven days after their release from custody: one conviction for incest means an offender is required to comply with reporting obligations for 15 years, while one conviction for incest with a class 2 offence or two or more convictions for incest means an offender is required to comply with reporting obligations for the remainder of their life.

### Papua New Guinea

Incest is illegal in Papua New Guinea.

### New Zealand

In New Zealand, incest is sexual connection between a parent and child (both biological and adopted), grandparent and grandchild (both biological and adopted), and full and half-siblings.
It is a defence if the person was unaware of the relationship at the time of the act (i.e. accidental incest). A conviction for incest attracts a maximum penalty of 10 years' imprisonment. Incest was the only sexual crime punishable by seven years or more imprisonment that was not subject to the country's "three-strikes" law before they were repealed in 2022.
Although the general age of consent for sexual activity is 16 in New Zealand, separate provisions under the law prohibit sexual contact with step-children, foster children and wards, even if they are aged 16 or 17. A conviction for having a sexual connection, or attempting to have a sexual connection, with a dependent child attracts a maximum penalty of seven years' imprisonment.