Israr Ahmad (Urdu: اسرار احمد; 26 April 1932 – 14 April 2010), was a Pakistani based Islamic scholar, orator and theologian.
He developed a following in South Asia but also among some  South Asian Muslims in the Middle East, Western Europe, and North America.
 He has written around 60 books on Islam and Pakistan, of which twenty nine have been translated into several other languages, including in English, as of 2017.
 In 1956 he left the Jamaat-e-Islami, which had become involved in electoral politics, 
to found Tanzeem-e-Islami.  Like many other Sunni Islamic activists/revivalists he preached that the teachings of the Qur'an and the Sunnah and divine law of Sharia must be implemented in all spheres of life, that the Caliphate must be restored as a true Islamic state, and that Western values and influences were a threat to Islam and Pakistan. He was also known for his belief that Pakistan, not Arab lands, should be the foundation for a new caliphate, that democratic governance was unislamic, and his opposition to Shi'i Islam.
 He was awarded the Sitara-i-Imtiaz, the third-highest civilian award of Pakistan, in 1981.
 Ahmad was born on 26 April 1932 in Hisar, Punjab. His father was a civil servant in the British government who relocated his family from Hisar to Montgomery, now Sahiwal, Punjab Province of Pakistan.
 After graduating from a local high school, Ahmad moved to Lahore to attend the King Edward Medical University in 1950. He received his MBBS degree from King Edward Medical University in 1954 and began practising medicine. In addition, he obtained his master's degree in Islamic Studies from the University of Karachi in 1965.
 Ahmad worked briefly for Muslim Student's Federation in the Independence Movement and, following the creation of Pakistan in 1947, for the Islami Jami`yat-e-Talaba and then in 1950 joined Jamaat-e-Islami led by Abul Ala Maududi. He left the party when the latter opted for participating in electoral politics in 1957 in the belief that involvement in national politics was irreconcilable with the revolutionary methodology adopted by the Jama'at in the pre-1947 period. His interest in Islam and philosophy grew further and he subsequently moved to Karachi in the 1960s, where he enrolled in Karachi University to study Islam.
 Supporters describe his vision of Islam as having been synthesised from the diverse sources.  Ahmad  worked closely with Syed Abul A'la Maududi  (1903–1979) and Amin Ahsan Islahi, (as did  Wahiduddin Khan, Naeem Siddiqui and Javed Ahmad Ghamidi). He has also acknowledged the "deep influence" of Shah Waliullah Dehlawi, the 18th century Indian Islamic leader, anti-colonial activist, jurist, and scholar.
 "In the context of Qur'anic exegesis and understanding, Ahmad was a firm traditionalist of the genre of Mahmud Hasan Deobandi and Shabbir Ahmad Usmani; yet he presented Qur'anic teachings in a scientific and enlightened way".
Ahmad believed in what he called "Islamic revolutionary thought," which consists of the idea that Islam – the teachings of the Qur'an and the Sunnah – must be implemented in the social, cultural, juristic, political, and economic spheres of life. In this he is said to follow Muhammad Rafiuddin and Muhammad Iqbal. The first attempt towards the actualisation of this concept was reportedly made by Abul Kalam Azad through his short-lived party, the Hizbullah. Another attempt was made by Abul Ala Maududi through his Jamaat-e-Islami party. Although the Jamaat-e-Islami has reached some influence, Ahmad resigned from the party in 1956 when it entered the electoral process and believed that such an involvement led to "degeneration from a pure Islamic revolutionary party to a mere political one".
 Originally a member of Jamaat-e-Islami, Ahmad stated that he became disappointed with its turn towards electoral activity, disagreed with it on "significant policy matters", including what he saw as the "lack of effort to create an Islamic renaissance through the revolutionary process."  He considered Jamaat-e-Islami's "plunge" into "the arena of power politics," to have been "disastrous." He and some other individuals resigned from JI and in 1956 founded the nucleus of Tanzeem-e-Islami, passing a resolution "which subsequently became the Mission Statement of Tanzeem-e-Islami."
 Along with his work to revive what he called "the Qur'an-centered Islamic perennial philosophy and world-view" Israr Ahmad stated that his goal and the goal of  his organizations was to "reform the society in a practical way with the ultimate objective of establishing a true Islamic State, or the System of Khilafah".
 In 1971 Ahmad gave up his  medical practice to "launch a movement for the revival of Islam".  "As a result of his efforts" the Markazi Anjuman Khuddam-ul-Quran Lahore was established in 1972, Tanzeem-e-Islami was founded in 1975, and Tahreek-e-Khilafat Pakistan was launched in 1991.
 Israr Ahmad was not well known and Tanzeem-e-Islami (TI) was relatively small until 1981 when President at the time Muhammad Zia-ul-Haq—who was working to "Islamize" Pakistan—asked the state-owned Pakistan television channel (PTV),  to give  Israr a weekly show. It became one of the first shows in Pakistan where a scholar "would sit in front of an audience and deliver lectures on Islam". Israr is thought to have been instrumental in bringing changes  to Pakistan TV during that time eliminating Western dress for women and requiring hijab. Israr later refused to appear on TV after segments of his program calling for a ban on televising cricket matches were  censored, but by then had developed a large following in Pakistan.
 Ahmad has authored over 60 books in Urdu on topics related to Islam and Pakistan, nine of which have been translated into English and other languages.
 Ahmad opposed modern democracy and the prevalent electoral system, arguing that in a true Islamic state the ruler   has the power to overturn the majority decisions of an elected assembly.
 While Israr Ahmad "considers himself a product" of the teachings of "comprehensive and holistic concept of the Islamic obligations" of Abul Ala Maududi, he opposed Jamaat-e-Islami's entry into "the arena of power politics". Instead he believed what was needed was a "revolutionary methodology" pursued by a "disciplined organization".
 While many, if not all, Sunni activists seek a return of the Caliphate, an  "important aspect of Ahmad's ideology" was his belief that "the foundations for the caliphate" should not be in Hijaz, Baghdad, or other more traditional sites, but rather in Pakistan, to where he believed that "the spiritual nerve center of the Islamic intellectual movement had shifted".
 Both Hizb ut-Tahrir and Tanzeem-e-Islami share a belief in the revival of the Caliphate as a means of implementing Islam in all spheres of life, according to Tanzeem-e-Islami's FAQ. However, Tanzeem-e-Islami seeks a popular Islamic revival which will then lead to political revolution rather than involvement in electoral politics, armed struggle, coup d'état to establish a caliphate.  Tanzeem-e-Islami believes that once the Islamic revolution has taken place, the election of the Khalifah would be done on the basis of electoral votes. Tanzeem-e-Islami emphasises that iman (faith) among Muslims must be revived in "a significant portion of the Muslim society" before there can be an Islamic revival.
 According to the website of Ahmad's organization, Tanzeem-e-Islam (as of 2017): 
 "We believe that an Islamic state can be established in Pakistan by means of a popular non-violent movement ... a coup d'etat can never produce a stable and positive change as it does not involve changing the beliefs and thoughts of the people."  However, critic Farhan Zahid notes that "a number" of the members of Tanzeem-e-Islam "have reportedly been arrested in connection with IS' Khurasan province and accused by the authorities of involvement in terrorist financing", and that "speeches" by Israr "still circulate online among jihadists, raising concerns that the group provides an entryway to Islamist extremism."
 Scholar Vali Nasr argues that in the 1980s Ahmad became part of Saudi Arabia's anti-Shiite campaign, particularly his "popular Friday sermons in Bagh-i Jinnah park in Lahore". The campaign  evolved from attacking Khomeini and his theories, to moving Shi'ism "outside the pale" of Islam,  to transforming "doctrinal and theological disputes into communal ones." This campaign eventually led to violence. 
As many as 4,000 people are estimated to have been killed by Shia-Sunni sectarian attacks in Pakistan between 1987 and 2007.
 In 1982 Ahmad generated controversy by  asserting that women should 'be barred from all professions except medicine and teaching".
 In a conversation with then-president Zia-ul Haq, Ahmad urged that the game of cricket be banned.
 
In some of his appearances before a TV studio audience, Ahmad complained:  "Cricket is making Pakistanis ignore their religious obligations, ... I am convinced that cricket matches should not be shown on TV." Ahmad also maintained that only men should be allowed to watch cricket matches. He later complained that bowlers were rubbing the cricket ball suggestively on their bodies.
 Ahmad  often expounded "conspiracy theories" about how "Jews and Israel" were attempting "to destabilize Pakistani society". He would include comments on the "Jew World Order", descriptions of "Jews as 'cursed people' or 'cursed race' who had conspired against Muslims for centuries", and  were 'followers of Satan, intent on destroying Islam'.
 Ahmad opposed the 2007 Pakistani state of emergency and in a televised press conference called for the resignation of President Pervez Musharraf. 
from both the presidency and chief of army staff.
 While on television, Ahmad  predicted and warned the nation that, "If the situation worsens, the NATO forces are waiting on the western front to move into Pakistan and may deprive the country of its nuclear assets while on the eastern front, India is ready to stage an action replay of Indo-Pakistani war of 1971 and has alerted its armed forces to intervene in to check threats to peace in the region."
 Asia Times reports that in September 1995 Ahmad told the annual convention of the Islamic Society of North America: "The process of the revival of Islam in different parts of the world is real. A final showdown between the Muslim world and the non-Muslim world, which has been captured by the Jews, would soon take place. The Gulf War was just a rehearsal for the coming conflict." He appealed to the Muslims of the world, including those in the US, to prepare themselves for the coming conflict.
 After the Demolition of the Babri Masjid in India, Israr criticised the vengeful demolition of Hindu temples in Pakistan, calling them unislamic and making the perpetrators the same as Hindu extremists in India.
 Ahmad relinquished the leadership of Tanzeem-e-Islami in October 2002 because of bad health. He had appointed Hafiz Akif Saeed (his son) the Emir of the Tanzeem (from 2002 to 2020) to whom all rufaqaa of Tanzeem renewed their pledge of Baiyah.
 Israr Ahmad died of cardiac arrest at his home in Lahore on the morning of 14 April 2010 at the age of 78. He had given up the leadership of Tanzeem-i-Islami in 2002 due to poor health. According to his son, his health deteriorated at around 1:30 am with pain in the back. He was a long time heart patient. His survivors included a wife, four sons and five daughters. His four sons, Arif Rasheed, Akif Saeed, Asif Hameed and Atif Waheed, have all been involved in Islamic activism.
 One major Pakistani English-language newspaper (Dawn) commented after his death, "Founder of several organisations like Anjuman-i-Khuddamul Quran, Tanzeem-i-Islami and Tehrik-i-Khilafat, he had followers in Pakistan, India and Gulf countries, especially in Saudi Arabia. He spent almost four decades in trying to reawaken interest in Quran-based Islamic philosophy."