Khan was born on 2 November 1965 into a Muslim family in New Delhi.^[17] He spent the first five years of his life in Mangalore, where his maternal grandfather, Iftikhar Ahmed, served as chief engineer of the port in the 1960s.^[18][19][e] Khan has described himself on Twitter as “half Hyderabadi (mother), half Pathan (father), and some Kashmiri (grandmother)”.^[21]

Khan grew up in the Rajendra Nagar neighbourhood of New Delhi.^[22] His father had several business ventures including a restaurant, and the family lived a middle-class life in rented apartments.^[23] Khan attended St. Columba’s School in central Delhi where he excelled in his studies and in sports such as hockey and football,^[24] and received the school’s highest award, the Sword of Honour.^[23] Initially Khan aspired to pursue a career in sports, however owing to a shoulder injury in his early years meant that he could no longer play.^[25] Instead, in his youth, he acted in stage plays and received praise for his imitations of Bollywood actors, of which his favourites were Dilip Kumar, Amitabh Bachchan, and Mumtaz.^[26] One of his childhood friends and acting partners was Amrita Singh, who became a Bollywood actress.^[27] Khan enrolled at Hansraj College (1985–88) to earn his bachelor’s degree in economics, but spent much of his time at Delhi’s Theatre Action Group (TAG),^[28] where he studied acting under the mentorship of theatre director Barry John.^[29][30] After Hansraj, he began studying for a master’s degree in mass communication at Jamia Millia Islamia, but left to pursue his acting career.^[31][32] He also attended the National School of Drama in Delhi during his early career in Bollywood.^[33]

His father died of cancer in 1981,^[f] and his mother died in 1991 from complications of diabetes.^[36] After the death of their parents, his older sister, Shahnaz Lalarukh (born 1960)^[37] fell into a depressed state and Khan took on the responsibility of caring for her.^[34][38] Shahnaz continues to live with her brother and his family in their Mumbai mansion.^[39]