Abdul Qadeer Khan, Indian-Pakistani physicist, chemist, and engineer
Abdul Qadeer Khan, NI, HI, FPAS ( (listen); Urdu: عبد القدیر خان; 1 April 1936 – 10 October 2021), known as A. Q. Khan, was a Pakistani nuclear physicist and metallurgical engineer who is colloquially known as the "father of Pakistan's atomic weapons program".

An émigré from India who migrated to Pakistan in 1952, Khan was educated in the metallurgical engineering departments of Western European technical universities where he pioneered studies in phase transitions of metallic alloys, uranium metallurgy, and isotope separation based on gas centrifuges. After learning of India's "Smiling Buddha" nuclear test in 1974, Khan joined his nation's clandestine efforts to develop atomic weapons when he founded the Khan Research Laboratories (KRL) in 1976 and was both its chief scientist and director for many years.

In January 2004, Khan was subjected to a debriefing by the Musharraf administration over evidence of nuclear proliferation handed to them by the Bush administration of the United States. Khan was accused of selling nuclear secrets illegally and was put under house arrest in 2004. After years of house arrest, Khan successfully filed a lawsuit against the Federal Government of Pakistan at the Islamabad High Court whose verdict declared his debriefing unconstitutional and freed him on 6 February 2009. After his death on 10 October 2021, he was given a state funeral at the Faisal Mosque before being buried at the H-8 graveyard in Islamabad.