Rhys Alun Williams, portrayed by Kai Owen, is a fictional character in the BBC television programme Torchwood, a spin-off from the long-running series Doctor Who. The character is introduced in the premiere episode as the co-habiting boyfriend of principal character Gwen Cooper. Initially a recurring character, Rhys' role is increased after the second series; actor Kai Owen is given star billing from the show's third series — a five-part serial subtitled Torchwood: Children of Earth — onwards. The character has gone on to appear in expanded universe material such as the Torchwood novels and audiobooks, comic books and radio plays.