Television
During the early 1960s, Martin was the resident singer of topical songs on the British weekly satire show That Was The Week That Was (1962–1963). The day after the assassination of President Kennedy, Martin sang the tribute song "In the Summer of His Years" on the show, which was composed by Herbert Kretzmer and David Lee just hours after the assassination. Her tribute was released as a single and 'bubbled under' the Billboard Hot 100 chart at No 104 in 1963 (but was outcharted by a cover version by Connie Francis, which reached No 46).
Martin won a BAFTA TV Award for Light Entertainment Personality in 1964. She has also released recordings in Swedish, such as the 7" single "Om du nånsin skulle ändra dej".
Martin had her own BBC television series between 1964 and 1966, titled Mainly Millicent for the first two series, and shortened to Millicent for the third and final series. For her work in this series she won the TV Society Award. In one episode, Martin and guest star Roger Moore performed a comedy skit in which Moore played secret agent James Bond some years before he was cast in the role. In the mid-1960s she guested, alongside Pete Murray and Kenneth Williams, in an edition of Juke Box Jury.
She appeared with Morecambe and Wise in their series "Two of a Kind" in the 1960s.
In 1969, Sir Lew Grade wanted to make a comedy film series, starring Martin, that would appeal to both American and British audiences. He sent six comedy sketches of Martin to producer Sheldon Leonard, who came up with the premise of From a Bird's Eye View. The series was not a success and was cancelled after 16 episodes had been filmed.
In 1977, on Jubilee Day, she appeared in a gala edition of BBC TV's The Good Old Days to celebrate the Queen's Silver Jubilee, performing in a double act with Julia McKenzie.
Martin appeared on $100,000 Pyramid in 1987 during the second week of the show's longest lasting tournament.
Martin appeared as Gladys Moon in 13 episodes of Moon and Son, a 1992 BBC detective series created by Robert Banks Stewart, and co-starring John Michie.
In 2005, she had a small part in the film Mrs. Palfrey at the Claremont which starred Joan Plowright.
Her later television roles include Gertrude Moon, Daphne Moon's Mancunian mother, in the American sitcom Frasier. She has worked for the Disney Channel, starring in the shows The Suite Life of Zack & Cody, Jonas and in the film Return to Halloweentown. Other performances include guest roles in The Drew Carey Show, Will & Grace, Newhart and Days of Our Lives. She also had a small role on an episode of Gilmore Girls and a key role in an episode of Modern Family.
In 2011, she guest-starred opposite her former Frasier daughter, Jane Leeves, in the TV Land series Hot in Cleveland. She has also had an appearance in the fourth season of Chuck as the mother of Hartley Winterbottom, who was given the first Intersect prototype and became Alexei Volkoff; she also guest-starred on an episode of the fourth season of Castle as a theatre critic who wrote a harsh review of a performance given by Castle's mother.
From 2017 to 2022, she appeared in Grace and Frankie as Joan-Margaret.
