The actress, who was born in Bradford, West Yorkshire, fought a long battle with cancer and died in hospital in London.
Agent Barry Langford, who confirmed the news, said she had a “zest for life”. “She was a darling companion and wonderfully witty and kind,” said Tom Baker, who played the fourth Doctor. “I’m so sorry to hear of her death.”
Colin Baker, who played the sixth Doctor, wrote on Twitter, “Shell-shocked to hear Mary Tamm is gone. A funny, caring, talented, lovely and down to earth lady.”
Tamm’s stage and screen career also included films The Odessa File and The Likely Lads, as well as recurring roles in EastEnders and Brookside.
“She was a fantastic actress,” said Langford, who was her agent for 22 years. “She played stage parts of such range, parts that would take your breath away. She could play any role, and do so wonderfully.”
Tamm, who lived in London, had been suffering from cancer for 18 months.
The actress played Romana, a Time Lady from the Doctor’s home planet of Gallifrey, alongside Tom Baker’s Doctor and his robot dog K-9 in a season of six connected stories in 1978-9. Her first story, The Ribos Operation, saw her join the Tardis crew on a quest to find the six scattered segments of the Key to Time. Romana’s other adventures included a story called The Pirate Planet, written by Douglas Adams, and The Stones of Blood, which was the 100th story since the sci-fi show started in 1963. When Tamm left Doctor Who the role of Romana was taken over by Lalla Ward.
Tamm trained at Rada, beginning her career at the Birmingham Repertory Theatre, alongside Derek Jacobi, Joan Sims and Ronnie Barker. Her stage work included the roles of Amanda in Private Lives and Beverley in Abigail’s Party. She moved on to work in television and film. Her first feature film was Tales That Witness Madness, with Kim Novak. More recently, she starred in Wire in the Blood, Paradise Heights and Jonathan Creek on TV.
Actress Helen Lederer, a friend of Tamm’s, said: “Mary was such an energised, talented woman with a great twinkle in her eye and she was so very beautiful.”
Tamm leaves behind husband Marcus Ringrose, daughter Lauren and seven-year-old grandson Max.
Mr Ringrose paid tribute to her “sheer talent”. “Mary was truly beautiful in every way. On set and offstage, her earthy northern humour and self-deprecating wit brightened every occasion.”
Her agent Langford revealed that Tamm had been saddened by the recent deaths of contemporaries Elisabeth Sladen, who played Sarah Jane Smith in Doctor Who, and Angharad Rees, who died last weekend. He said: “All of these people who she knew were going.”