In 1994, Rippy moved to England and was a member of the theatre group the Reduced Shakespeare Company.
In a recent television appearance, Rippy portrayed the namesake of Jack Harkness of Torchwood in the first series' twelfth episode Captain Jack Harkness. In the episode, Captain Jack (Rippy) was a young American volunteer serving as an RAF Group Captain stationed in Cardiff. He was in a heterosexual relationship, and was eventually revealed to be attracted to Torchwood's Jack, who after an unfortunate "temporal shift", landed in 1941 during the height of the Cardiff blitz.
Matt Rippy also starred in the fourth series of Ultimate Force, in the final episode, "Slow Bomb".
He appeared in an episode of the BBC's Bonekickers on 29 July 2008. He appeared in episode 4, "The Cradle of Civilisation" as an illegal looter of Babylonian artefacts.
The actor appeared in The Dark Knight, as the first mate aboard a hostage ship of civilians.