Writer of historical novels and portrait painter. Born Dorothy Halliday in Dunfermline (Fife), Dunnett was educated at Gillespie's High School for Girls in Edinburgh, followed by the Edinburgh College of Art and Glasgow School of Art. In 1946, she married Alistair Dunnett, who was Editor of the Scotsman newspaper for sixteen years and fourteen years her senior, and the couple made Edinburgh their home. She began her career in the Civil Service, but went on to become a professional portrait painter and sculptor, with her work exhibited at the Royal Scottish Academy. However, Dunnett found fame as the writer of extensively researched historical romances. Her first novel was Game of the Kings (1961), which grew into the six-volumes of The Lymond Chronicles; more recent work includes King Hereafter (1976) and Niccolo Rising (1986).
She was awarded an OBE in 1992 and served as a Trustee of the National Library of Scotland and of the Scottish National War Memorial.
She died in Edinburgh.