Terence Arthur De Marney (1 March 1908 – 25 May 1971) was a British film, stage, radio and television actor, as well as theatre director and writer.

Thrillers tended to be his stock in trade, appearing in a revival of Sutton Vane's Outward Bound during the 1930s, as well as Agatha Christie's Ten Little Indians and Dear Murderer.

After starring in 'B' films Dual Alibi (1948), and No Way Back (1949), he uprooted to Hollywood, where he appeared in a number of famous television series such as Bonanza, Wagon Train, Maverick, Thriller, and The Twilight Zone.

He was a series regular in the role of Case Thomas on CBS's Johnny Ringo, with Don Durant, Mark Goddard, and Karen Sharpe.

With Percy Robinson he wrote the stage thrillers The Whispering Gallery, Wanted for Murder and The Crime of Margaret Foley; he collaborated with Ralph Stock to write Search.