Saira Banu was born to actress Naseem Banu, and film producer Mian Ehsan-ul-Haq, who had produced, "Phool" in Mumbai and "Wadah" in Pakistan. Her maternal grandmother was the courtesan namely, Chamiyan Bai, also known as Shamshad Begum of Delhi (not the famous playback singer of yesteryear Shamshad Begum who was from Amritsar, Punjab). Saira spent a significant part of her childhood in London.
At the age of 16 (in 1960), she debuted in the Hindi films with the basic acting talent and dancing experience. However, she started taking Kathak and Bharat Natyam classes to accentuate her professional career. Her acting debut was in "Junglee" (in 1961), opposite Shammi Kapoor, with whom she did another movie named "Bluff Master", directed by Manmohan Desai. She earned her first Filmfare nomination as Best Actress for this film and also made her successful instantly, which lasted throughout the 1960s and early 1970s.
She has created an image of a romantic heroine. Some of her romantic films include "Jhuk Gaya Aasman" and "Aayi Milan Ki Bela" (with Rajendra Kumar), and "April Fool" (with Biswajeet), and five films with Joy Mukherjee - "Door Ki Awaz", "Aao Pyaar Karen", "Shagird", "Yeh Zindagi Kitni Haseen Hai" and "Saaz Aur Awaaz".
Saira also did a double role in the film, "Yeh Zindagi Kitni Haseen Hai". Post marriage (in 1966), her first film to release was "Aman", opposite Rajendra Kumar. She continued to act as the lead heroine till 1977.
The turning point came with the comedy and love story "Padosan" (in 1968), opposite Sunil Dutt, which got her to the top list of the most successful actresses, and she started receiving more offers. Some of her films are with Navin Nischol, like "Victoria No. 203" and "Paise Ki Gudiya". She earned three additional Filmfare nominations as Best Actress for "Shagird" (1967), "Diwana" (1968), and "Sagina" (1974). Along with "Sagina", her pairing with her husband, Dillip Kumar, was for the films, "Bairaag", and "Gopi" (which was quite successful at the box office). She also had a good pairing with Dharmendra in "Jwar Bhata", "Aadmi Aur Insaan", "Resham Ki Dori", "Pocket Maar", "International Crook" and "Chaitali". She did three films with Manoj Kumar namely, "Shaadi", "Poorab Aur Paschim" and "Balidan"; "Pyar Mohabbat" with Dev Anand"; and "Aarop" with Vinod Khanna. Her last film; "Faisla", opposite to Vinod Mehra was completed in 1976, released in 1988.
Saira was the third highest paid actress in Hindi Cinema from 1963 to 1969 and the fourth highest paid actress from 1971 to 1976.