After training in acting and dancing, she took a part as a school girl in STV's production of The Prime of Miss Jean Brodie where she was credited as Dory Hepburn. She starred in the 1981 film Gregory's Girl playing John Gordon Sinclair's love interest Dorothy, for which she won the Variety Club actress of the year award. Unlike most of the cast, who were sourced from the Glasgow Youth Theatre, Hepburn was spotted by Bill Forsyth dancing in a television commercial for a Scottish department store. The film's cast reunited for the 30th anniversary of its release in 2010, and a clip from the film featuring Hepburn was part of the opening ceremony from the London 2012 Summer Olympics.
She was offered various roles after the success of Gregory's Girl, including the female lead opposite Oliver Reed in Castaway (played by Amanda Donohoe), and the lead in Bolero (played by Bo Derek), she turned them down because of the required level of nudity and sexual content, and having to work away from her Scottish home. She started a career in television, appearing in the Glasgow set series Maggie, and presenting It's a Knockout.
After moving south to live in Cheltenham, Gloucestershire with her then fiancé Brian Ruane a former footballer with Motherwell, she took a role in the soap opera Crossroads for three years as the receptionist Anne-Marie Wade.
After returning to East Kilbride, she married and had two children. She and the father broke up when the children were young, resulting in a brief comeback with a role in the film The Bruce (1996), alongside Oliver Reed.
- Frances Hardy (9 February 2013). "Why Gregory's Girl Dee Hepburn turned her back on fame". Daily Mail. Retrieved 9 February 2013.
- "Dee Hepburn, Schemes and Dreams - BBC Radio Scotland". BBC. Retrieved 2017-01-15.
Des Clarke talks to Dee Hepburn about life growing up in East Kilbride and her rise to fame after starring in the 1981 blockbuster Gregory's Girl. Returning to Rockhampton Avenue, Dee gets an opportunity to take a step back in time when she is invited into the old family home by the new owners.
- "Dee Hepburn". STV. Archived from the original on 4 December 2013. Retrieved 9 February 2013.
- Jane Graham (4 March 2010). "Gregory and his girls reunited in Glasgow". The Guardian. Retrieved 9 February 2013.
- Tim Walker (29 July 2012). "Gregory's Girl goes for Olympic gold". Daily Telegraph. Retrieved 9 February 2013.