# SO

SO or so may refer to:

## Arts and entertainment
### Music

* So (album), an album by Peter Gabriel
* So (band), a duo from the 1980s formed by two members of The Opposition
* "So" (Static-X song), a song by Static-X
* "Sō (New Love New World)", a song by Masaharu Fukuyama
* "So", a song by War from Why Can't We Be Friends?
* "So", a song by Fates Warning from Disconnected
* S.O. (rapper)

### Other

* "SO" (Sons of Anarchy), the third season premiere of the FX television series Sons of Anarchy
* So Television, a British TV production company

## Relationships

* Significant other, a partner in an intimate relationship

## Businesses

* Austrian Air Services (former IATA airline designator SO)
* Sosoliso Airlines (former IATA airline designator SO)
* Southern Airways (former IATA airline designator SO)
* Southern Company (stock symbol SO)
* Superior Aviation (IATA airline designator SO)

## Language

* So language (Democratic Republic of Congo), a Bantu language
* Sô language, a Katuic language (Mon-Khmer) of Laos and Thailand
* Swo language, a Bantu language of Cameroon
* Soo language, a Kuliak language of Uganda
* Somali language (ISO 639 language code "so")
* So (kana), a Japanese kana
* So (word), an English word

## Places

* So, Iran, a village in Isfahan Province, Iran
* Canton of Solothurn, Switzerland
* So Phisai District, Bueng Kan Province, Thailand
* SO postcode area, UK, the Southampton postcode area
* Somalia (ISO 3166-1 alpha-2 country code SO)
* South Otago, part of New Zealand's South Island
* Southern State Parkway, a highway in New York, United States

## Science, technology, and mathematics
### Biology and medicine

* Syndromic obesity, excess body fat occurring as part of a syndrome
* Sphincter of Oddi, a muscular valve of the duodenum

### Computing

* .so, the top-level Internet domain of Somalia
* .so, a filename extension for a shared object (a dynamic library or module) in Unix and Linux
* Shift Out, an ASCII control character in computing
* Small-outline integrated circuit
* StackOverflow, a programming Q&A site

### Mathematics

* SO (complexity), second-order logic in descriptive complexity
* Special orthogonal group, a subset of an orthogonal group
** SO(2), a term used in mathematics, the group of rotations about a fixed point in the Euclidean plane
** SO(3), a term used in mathematics, the group of rotations about a fixed point in three-dimensional Euclidean space
** SO(4), a term used in mathematics, the group of rotations about a fixed point in four-dimensional Euclidean space
** SO(5), a term used in mathematics, the special orthogonal group of degree 5 over the field R of real numbers
** SO(8), a term used in mathematics, the special orthogonal group acting on eight-dimensional Euclidean space
** ${\mathfrak {so}}(n)$, the corresponding special orthogonal Lie algebra

### Physics and chemistry

* Sulfur monoxide
* SO(10) (physics), a term used in particle physics, one of the grand unified theories is based on the SO(10) Lie group

## Names

* Sō, a Japanese surname and given name
* Su (surname) (苏/蘇), a Chinese surname and a Korean surname (소) derived from it
* So (Korean name) (蘇 or 邵)

## Other uses

* So (סוֹא), King of Egypt, usually identified with Osorkon IV
* So (dairy product), a type of dairy product made in ancient Japan
* Sales order, an order received by a business from a customer
* Sao civilisation or So, an African civilisation and population that flourished from ca. the 6th century to ca. 15th century
* Shell on, a form of presentation in shrimp marketing
* Strikeout, in baseball