Denis Clifford Quilley (b. December 26 1927, Islington, North London - d. October 52003) was an English theatre, television and film character actor who was long associated with the Royal National Theatre.

A generation of children grew up with his portrayal of Commander Traynor in the children's science fiction TV series Timeslip. He was also heard in many television voiceovers.

He had long runs on London's West End during the 1950s in Wild Thyme and Grab Me a Gondola. In the 1970s he appeared with the Royal National Theatre in Macbeth, Hamlet, The Tempest and Long Day's Journey Into Night, alongside Laurence Olivier in the last. In 1980, he played the title role in Stephen Sondheim's Grand Guignol musical Sweeney Todd and in 1982 he played Terri Dennis in Peter Nichols' play, Privates on Parade (he appeared in the film version of Privates on Parade as well).

He appeared in two film version of Agatha Christie's classic mystery novels, as Captain Kenneth Marshall in Evil Under the Sun and as the Italian, Antonio Foscarelli in Murder on the Orient Express.

His screen appearances grew increasingly rare in later life, one of his few starring appearances being as Saint Peter in the international drama mini-series, A.D..

He did the voice of Molokov, a second to a Russian chess champion on the concept album of the musical Chess in 1984.

One of his last stage performances was as Elisha Whitney in a Cole Porter revue. He was to have been in the musical Anything Goes at the Theatre Royal Drury Lane, but was too unwell to make the transfer from the National Theatre to the West End.

He was working on his autobiography (ISBN 1-84002-268-X) in the months before he died at his home in London, aged 75, from liver cancer.

Noted British classical theatre actor Denis Quilley distinguished himself on the Shakespearean stage alongside Laurence Olivier and John Gielgud, among others. His sturdy handsomeness was slightly offset by a relatively prominant probiscus which, like Jeremy Northam and Liam Neesom, enhanced the look and added to the uniqueness of his characters. Educated at Bancroft's School in Essex, he made his first appearance in 1945 with the Birmingham Repertory Company and replaced Richard Burton in "The Lady's Not for Burning" in his London debut in 1950. Following roles in "Twelfth Night" and "The Merchant of Venice," Quilley took a marked departure from his classical reputation and made a resounding hit for himself in musicals and satirical revues, notably "Airs on a Shoestring" (1953) and "Grab Me a Gondola."(1956). In the early 60s he took his London role in "Irma La Douce" to Broadway and met with great success. Over his nearly six-decade career, he would grace the Old Vic, Royal Shakespeare, Regent's Park and Drury Lane stages in a wide range of roles. Highlights have included his Lopakhim in "The Cherry Orchard" and Claudius in "Hamlet." In the 70s he joined Laurence Olivier's National Theatre Company for its last seasons at the Old Vic. He played Jamie to Olivier's James Tyrone in "Long Day's Journey Into Night" (also a TV version), Hildy Johnson in "The Front Page" and Caliban in "The Tempest" with Gielgud. He continued impressively in musicals winning kudos for his "Sweeney Todd" and for "La Cage Aux Folles." He ended his career with "Anything Goes" in 2003, the year of his death. A less frequent but still familiar face on television ("Masada") as well as in film intrigue ("Murder on the Orient Express," "Evil Under the Sun"), the versatile Quilley was a gifted, cerebral player who could display strength as well as vulnerability and weakness.