She also co-founded Hamilton-Mehta Productions, with her husband, producer David Hamilton in 1996. She was awarded a Genie Award in 2003 for the screenplay of Bollywood/Hollywood. In May 2012, Mehta received the Governor General's Performing Arts Award for Lifetime Artistic Achievement, Canada's highest honour in the performing arts.
Mehta was born in Amritsar, Punjab though her family moved to New Delhi while she was still a child, and her father worked as a film distributor. Subsequently, Mehta attended Welham Girls High School, a boarding school for girls in Dehradun and graduated from the Lady Shri Ram College for Women, University of Delhi with a degree in philosophy.
After completing her graduation, Mehta started making short documentaries in India, and in time she met Canadian documentarian Paul Saltzman, who was in India making a film and whom she was to later marry and migrate with to Canada in 1973. Once in Canada, she embarked on her film career as a screenwriter for children's films, she also made a few documentaries including,At 99: A Portrait of Louise Tandy Murch (1975). In 1991 she made her feature-film directorial debut with Sam & Me (starring Om Puri), a story of the relationship between a young Indian boy and an elderly Jewish gentleman in the Toronto neighbourhood of Parkdale. It won Honorable Mention in the Camera d'Or category of the 1991 Cannes Film Festival. Mehta followed up with Camilla starring Bridget Fonda and Jessica Tandy in 1994. In 2002, she directed Bollywood/Hollywood, for which she won the Genie Award for Best Original Screenplay.
Mehta directed two episodes of George Lucas' television series The Young Indiana Jones Chronicles. The first episode, "Benares, January 1910", aired in 1993. The second episode was aired in 1996 as part of a TV movie titled Young Indiana Jones: Travels with Father.
Mehta also directed several English-language films set in Canada, including The Republic of Love (2003) and Heaven on Earth (2008) which deals with domestic violence and has Preity Zinta playing the female lead. The film premiered at the 2008 Toronto International Film Festival.
In 2015, Mehta wrote and directed the crime thriller film Beeba Boys (2015) a film starring Randeep Hooda as Jeet Johar, a proud observant Sikh and a ruthless gangster. The film is set to premiere at the 2015 Toronto International Film Festival.
Mehta is best known for her Elements Trilogy, Fire (1996), Earth (1998) (released in India as 1947: Earth), and Water (2005), which won her much critical acclaim. Some notable actors that have worked in this trilogy are Aamir Khan, Seema Biswas, Shabana Azmi, Kulbhushan Kharbanda, John Abraham, Rahul Khanna, Lisa Ray, and Nandita Das. These films are also notable for Mehta's collaborative work with author Bapsi Sidhwa. Sidhwa's novel Cracking India, (1991, U.S.; 1992, India; originally published as Ice Candy Man, 1988, England), is the basis for Mehta's 1998 film Earth. Mehta's film Water was later published by Sidhwa as the 2006 novel Water: A Novel. All three films have soundtracks composed by A. R. Rahman.
Water is the story of an eight-year-old child widow who is forced to enter a house of widows for the rest of her life. The film, meant to be shot in India, was attacked by Hindu fundamentalists. Riots broke out, sets were destroyed and death threats were issued towards the actors and Mehta, forcing the film to stop production. Four years later the movie was made in Sri Lanka. Water opened the 2005 Toronto International Film Festival and was nominated for an Academy Award for Best Foreign Language Film in 2006.
Mehta collaborated on the screenplay for Midnight's Children with the novel's author, Salman Rushdie. British-Indian actor Satya Bhabha played the role of Saleem Sinai while other roles were played by Shriya Saran, Seema Biswas, Shabana Azmi, Anupam Kher, Siddharth Narayan, Rahul Bose, Soha Ali Khan, Shahana Goswami and Darsheel Safary. The film was released on 9 September 2012 at Toronto International Film Festival.
In Canada she met and married filmmaker Paul Saltzman whom she divorced in 1983. The couple have a daughter, Devyani Saltzman, an acclaimed author, curator and cultural critic.
Mehta is currently married to producer David Hamilton. Her brother, Dilip Mehta, is a photojournalist and film director, who directed Cooking with Stella, which he co-wrote with Deepa.
In May 2013, Mehta received an honorary degree from Mount Allison University.Sam & Me (1991)
The Republic of Love (2003)
The Forgotten Woman (2008) (documentary - writer)
Heaven on Earth (2008)
Midnight's Children (2012) - based on the novel by Salman Rushdie
Beeba Boys (2015)
Anatomy of Violence (2016)
Doctor of Laws, University of Victoria, 2009
Governor General's Performing Arts Awards for Lifetime Artistic Achievement, 2012
Member of the Order of Ontario, 2013
Officer of the Order of Canada, 2013