Landor was born in Hampstead, London, the daughter of English actor and radio presenter Neil Landor and of an Irish mother. Landor was educated at the Royal Ballet School, Richmond, and at Tolworth Girls' School, in Surrey. A child Actress in British films in the late 1960s and early 1970s, she began her career at the age of nine, when she appeared in the Hammer Horror film The Devil Rides Out (1968).

In 1970 she appeared with Susannah York in Jane Eyre, playing Helen Burns. She co-featured in the film The Amazing Mr Blunden (1972), based on the book The Ghosts by Antonia Barber, and appeared opposite Richard Burton and Elizabeth Taylor in the TV movie Divorce His, Divorce Hers in 1973. She had many appearances on British and American television during the 1980s, as Polly Hampton in Thames Television's Love in a Cold Climate, Rumpole of the Bailey (as Fiona Allways in four episodes in 1983) and C.A.T.S. Eyes (starring as Pru Standfast in 1985). She played Guinevere in the TV movie Arthur the King (1985), and appeared in the role of Helen Stoner in Granada's TV adaptation Sherlock Holmes (The Speckled Band) opposite Jeremy Brett.

Landor moved to the west coast of the US in the second half of the 1980s. She now has two daughters, Arielle and Sophia, and lives in London. She continues with her career, including voice work for Disney and audiobooks for Random House as a narrator.

Her theatre roles have included Sorel in Hay Fever by Noël Coward in London's West End in 1984 with Penelope Keith and Moray Watson, and Raina in Shaw's Arms and the Man at Leicester's Haymarket Theatre opposite Malcolm Sinclair.

In the United States, Landor's television guest appearances have included Star Trek: The Next Generation (in the 1989 episode "Up the Long Ladder"), Matlock and Hunter. She also appeared as Britt in the 1990 film Bad Influence opposite Rob Lowe and James Spader.