David Hattersley Warner (29 July 1941 – 24 July 2022) was an English actor. Born on 29 July 1941 in Manchester, he studied at the Royal Academy of Dramatic Art and worked in theatre before achieving screen fame in the early 1960s with his leading role in Karel Reisz's film Morgan: A Suitable Case for Treatment, for which he was nominated for a BAFTA Award for Best Actor in a Leading Role.

Warner played both romantic leads and villainous characters across various media, including The Ballad of Cable Hogue, Straw Dogs, The Iron Cross, The Omen, Holocaust, The Thirty-Nine Steps, Time After Time, Time Bandits, Tron, A Christmas Carol, Portrait in Evil, Titanic, Mary Poppins Returns, and various characters in the Star Trek franchise, in the films Star Trek V: The Final Frontier and Star Trek VI: The Undiscovered Country, as well as in the television series Star Trek: The Next Generation.

In 1981 he received an Emmy Award for Best Supporting Actor in a Miniseries or Special for his role as Pomponius Falco in the television miniseries Masada.

He died on 24 July 2022 at the age of 80.