Amjad Khan was born in Peshawar, British India to legendary actor Jayant aka Zakaria Khan (father) and Qamar (mother) in a Pashtun family. His brothers are actors Imtiaz Khan and Inayat Khan. Khan was educated at St.Andrew's High School, in Bandra. He attended R D National College where he was the general secretary. In 1972, he married Shehla Kha. The couple had three children, two sons, Shadaab Khan and Seemaab Khan and a daughter, Ahlam Khan. He died in 1992 after suffering from heart failure at the age of 51.
Before Amjad Khan came to films, he was a theatre actor. His first role was as a child artist in the film Nazneen (1951). In 1973 he made his debut as an adult in Hindustan Ki Kasam. In 1975 he was offered the role of dacoit Gabbar Singh for the film Sholay by Salim Khan. Amjad shot to stardom with the movie. He dubbed a song in Shatranj Ke Khiladi (1977). He ventured into directing for a brief period in the 1980s, directing and starring in Chor Police (1983).
He was the president of the Actors Guild Association.