Amrita's paternal great-grandfather, Sir Sobha Singh, was a noted civil contractor who not only made a substantial fortune during the building of New Delhi in the early decades of the 20th century, but also received a knighthood for his efforts. His younger son, and Amrita's paternal granduncle, is the rebnowned littérateur Khushwant Singh. Her mother was Rukhsana Sultana who was famous for being Sanjay Gandhi's friend and influence peddler during the Emergency years in the 70's. Her parents were divorced when she was very young. She went to Modern School in Delhi.
Amrita was initially a belly dancer, but then tried out with cinema.
Amrita's mother was influential in launching her daughter's career in Hindi cinema. She lobbied with B.R. Chopra who was looking for a fresh face for his film "Nikah". Having already rejected Zeenat Aman (who played the lead in his previous mega success "Insaf ka Tarazu") he decided on Salma Agha. Rukshana Sultan was miffed and wrote threatening letters to Salma Agha in hopes of scaring the British raised girl to run back to London. The controversy over the anonymous letters grew and the letters were finally traced back to Amrita Sigh, however, much after Betaab was already on the floors. Salma Agha went on to do Nikaah, Zeenat Aman moved on to another mega success, Qurbaani and Amrita Singh got her success with Betaab, however, her reputation was tarnished.
Amrita made her Bollywood debut in 1983 with Betaab, a vastly successful film in which she paired with the debutant Sunny Deol. This was quickly followed by a succession of hits, such as Sunny in (1984); Mard which was the biggest hit of that year, and Saaheb in (1985); Chameli Ki Shaadi and Naam in (1986); Khudgarz in (1987), and so on. Amrita made a successful pair in several films not only with Sunny Deol and Sanjay Dutt, but also with Anil Kapoor and Amitabh Bachchan, two leading actors of the 1980s. As well as playing leading roles, she also played supporting negative roles in films such as Raju Ban Gaya Gentleman (1992) and Aaina (1993). She also won the Filmfare Best Supporting Actress Award for the latter. These successes did not dissuade her from her resolve to retire into family life, and Amrita quit acting after 1993. She returned to acting in 2002 with the film 23rd March 1931: Shaheed where she played the mother of Bhagat Singh (played by Bobby Deol). She then appeared on the STAR Plus television serial, Kavyanjali in 2005. Later that year she won acclaim for her performance in yet another negative role for the film Kalyug.
In 2007, Amrita played the role of the gangster Maya Dolas's mother, Ratnaprabha Dolas, in the Sanjay Gupta film Shootout at Lokhandwala, directed by Apoorva Lakhia. Vivek Oberoi played the role of Maya. Her last release was the anthology film Dus Kahaniyaan where she appeared in the short story Poornmasi.
In 1991, Amrita gave up acting for a family life with actor Saif Ali Khan, who is 12 years her junior. The couple have two children, a daughter Sara and a son Ibrahim.
They were separated in 2004 and Amrita Singh now lives with her two children.
She was said to have an affair with actor Sunny Deol. Also, she is the first cousin of actor Ayub Khan as her and Ayub's mothers are sisters.
Her nickname is Dingy.