She was born in Bombay, India, and educated at Heidelberg University in Germany and later at the Central School of Speech and Drama in London, England. She is best-remembered on television for her co-starring role in the early 1980s ITV children's fantasy series Into the Labyrinth as the evil witch Belor, and her late 1980s guest role in the BBC's popular soap opera EastEnders as shady mafia affiliate Joanne Francis. She has also been seen in two separate adventures of the BBC's long-runningscience-fiction series Doctor Who: as Toos in The Robots of Death (1977) and as Professor Rachel Jensen in Remembrance of the Daleks (1988), a role she reprised for the Big Finish spin off series, Countermeasures. She was also heard as one of the many voices of Xoanon in The Face of Evil (1977). She had previously auditioned for the role of the Fourth Doctor's companion Leela, but the role eventually went to Louise Jameson instead. Salem also had a recurring role in the British sitcom French Fields between 1989-91.
Other television guest appearances have included roles in popular British series such as Out of the Unknown, Blake's 7, The Onedin Line, The Professionals, Howards' Way, Ever Decreasing Circles, Tripods and All Creatures Great and Small, and more recently in American series including Magnum, P.I., Party of Five, ER, and The West Wing where she played a British prime minister.
In film, she played the role of Miss Moneypenny in the 'unofficial' 1983 James Bond film Never Say Never Again, starring Sean Connery. She also appeared in Michael Crichton's The Great Train Robbery (1979, another film which also starred Connery), as well as supporting roles in The Bitch (1979) and Gods and Monsters (1998).
She can also be heard as the Queen in the English dub of "Hellsing Ultimate OVA IV" (2008).
She is married to the actor Michael O'Hagan, and they currently live in Los Angeles.