Diane "Di" Trevis (born 8 November 1947) is an English theatre director and actress.
Trevis was born in Birmingham and educated at Sussex University.
After eight years as an actress, Trevis began directing in 1981.
She was the first woman to run a company at Britain's Royal National Theatre. Between 1986 and 1993, she directed Happy Birthday Brecht, The Mother, The School for Wives, Yerma, The Resistible Rise of Arturo Ui and Inadmissible Evidence for the National. In 2000 she adapted for the stage, with Harold Pinter, Pinter's unfilmed cinema adaptation of Proust's Remembrance of Things Past. The production, which transferred to the Olivier stage in 2001, was described as "ravishing" by critic Nicholas de Jongh in the Evening Standard and won an Olivier Award.
Trevis has also worked extensively at the Royal Shakespeare Company, with productions of Happy End, The Taming of the Shrew, The Revenger's Tragedy, Much Ado About Nothing and Elgar’s Rondo. In 1991 she mounted a production of Harrison Birtwistle's opera Gawain at the Royal Opera House. She also directed The Merry Widow for Scottish Opera and The Voluptuous Tango for the Almeida.