She passed away on Tuesday morning in a London hospital following an 18-month battle with cancer, her agent confirmed.
Tamm first appeared as in Doctor Who in the 1978 serial The Ribos Operation and stayed with the Doctor for the duration of the show's 16th season (often referred to as the"'Key to Time" series because of its linked storylines). She bowed out of the sci-fi drama at the end of The Armageddon Factor in 1979, when her character "regenerated" and Lalla Ward took over the role.
Born in Bradford, West Yorkshire, Tamm enjoyed a long and varied career on stage and screen. As well as Doctor Who, she appeared in feature films including The Odessa File and The Likely Lads and played recurring roles in soaps Brookside and EastEnders.
Her agent Barry Langford said: "She had a great zest for life. She was a fantastic actress – she played stage parts of such range, parts that would take your breath away. She could play any role, and do so wonderfully."
Beginning her career at the Birmingham Repertory Company, Tamm worked on stage alongside the likes of Joan Sims, Ronnie Barker and Derek Jacobi before moving into film and TV and notching up early credits in Coronation Street, The Donati Conspiracy and Freddie Francis’s film Tales That Witness Madness.
Remaining a presence on TV throughout her career, she recently starred in Wire in the Blood, Paradise Heights and Jonathan Creek.
Tamm also returned to Doctor Who in recent years, reprising the role of Romana in a series of Big Finish’s Doctor Who audio adventures. In 2009, she published her autobiography First Generation.
Tamm is survived by her husband Marcus Ringrose, daughter Lauren and seven-year-old son Max.