Portrait of a Marriage is a British television miniseries detailing the real-life love affair between Vita Sackville-West and Violet Keppel, as well as the strength of Vita's enduring marriage to the diplomat Harold Nicolson. Based on the biography of the same name by Nigel Nicolson, it features Janet McTeer as Vita, and Cathryn Harrison as Violet.

The series was adapted by Penelope Mortimer, directed by Stephen Whittaker and produced by Colin Tucker. It was first aired on BBC Two in four parts in 1990; a three-part edited version aired in the United States on PBS in 1992 as part of the Masterpiece Theatre strand.