Harriet Deborah Vane, Lady Peter Wimsey, is a fictional character in the writings of Dorothy L. Sayers. Daughter of a country doctor and graduate of the fictional Shrewsbury College, Oxford, Vane is a writer of detective stories who is wrongly accused of the murder of her former lover Philip Boyes. While she is on trial (in Strong Poison), Lord Peter Wimsey comes to her rescue by proving who really poisoned Boyes. After a courtship that continues through Have His Carcase and Gaudy Night, they marry in Busman's Honeymoon and move into an old country house she had admired as a child, Talboys. Thrones, Dominations takes place shortly after they return from their honeymoon. The first of their children is born in the story "The Haunted Policeman," and by the time of the story "Talboys" they have three sons: Bredon Delgardie Peter Wimsey (born in October 1936), Roger Wimsey (born 1938), and Paul Wimsey (born 1940).

Sayers consciously modeled Vane on herself, although perhaps not as closely as her fans (and even friends) sometimes thought. Vane's relationship with Boyes -- during which she agrees to live "in sin" with him on the basis of his claim not to believe in marriage and later, when he decides he wants to marry her after all, breaks off the relationship on account of his hypocrisy -- is based on Sayers's love affair (1921-1922) with the author John Cournos (1881-1956), a Russian Jew whose family emigrated to the U.S. when he was ten years old.