The son of a Welsh Congregationalist preacher, he moved with his family to Canada from Haverfordwest, Wales, at the age of seven, where he attended Upper Canada College. His most famous role is that of vampire turned police detective Nick Knight on the television series Forever Knight. Previous to this role, he had also played a vampire in Dracula: The Series.
His recent television roles include 24 in early 2006, as James Nathanson and ReGenesis in 2008 as Carleton Riddlemeyer. He also played cyber-terrorist David Kaydick in RoboCop: Prime Directives, and also portrayed maverick U.S. Air Force pilot Mike Rivers in the fourth and final season of Airwolf. He played Nick Haskell on the Canadian series Black Harbour, and Henry Breedlove in the second season of Slings and Arrows.
He appeared several seasons with the Shaw and Stratford festivals. He recently appeared in New York City with Christopher Plummer in King Lear, and in Washington, D.C. in the title roles of both Cyrano de Bergerac and Richard III.
Geraint Wyn Davies was married to fellow Canadian artist Alana Guinn from 1985-2006, with whom he has two children, daughter Pyper and son Galen. He has been involved with actress Claire Lautier for several years.