He is known for his roles in The Patriot, The Hi-Line, LD 50 Lethal Dose, Thunderbirds, CSI: Miami, King Lear, Strike Back, Flyboys, In My Sleep,[1] The Heart of the Earth and Shaking Dream Land.

After graduating from high school, he began to take roles in plays, including that of Edmund in King Lear opposite Ian McKellen, in the 2007 Royal Shakespeare Company production.

Winchester has also appeared in the films Solomon Kane (2009) (as a former member of the title character's crew, turned freedom-fighter) and In My Sleep (2010) (as the lead),[1] and the Syfy TV mini-series Alice.

From 2010, he has played the role of Frank Stanton, parallel universe fiance of Olivia Dunham, in the Fox TV series Fringe.

Michael Stonebridge (Winchester) and American former Delta Force officer Damien Scott (Sullivan Stapleton).