Violet Trefusis (née Keppel; 6 June 1894 – 29 February 1972) was an English socialite and author. She is chiefly remembered for her lengthy affair with the writer Vita Sackville-West that both women continued after their respective marriages. It was featured in novels by both parties; in Virginia Woolf's novel Orlando: A Biography; and in many letters and memoirs of the period roughly from 1912 to 1922. She may have been the inspiration for aspects of the character Lady Montdore in Nancy Mitford's Love in a Cold Climate and of Muriel in Harold Acton's The Soul's Gymnasium (1982).