Clotworthy has worked in over 100 feature films and television programs. He appeared as "Forensic Technician" in four episodes of the 1980s U.S. TV series Hunter. Clotworthy was the narrator on the Emmy nominated documentaries Empire of Dreams: The Making of the Star Wars Trilogy and Star Wars: The Legacy Revealed. Clotworthy even worked on The Lego Movie Videogame. Clotworthy also narrated Indiana Jones and the Ultimate Quest and Batman Unmasked: The Psychology of the Dark Knight. Clotworthy is also known for voicing the character Marshall Law in both Tekken 5 and its expansion, Tekken 5: Dark Resurrection. He has guest starred on The Big Bang Theory, Two and a Half Men and on China, IL. In 2014, Clotworthy voiced the Espheni (referred to as "The Monk") in the TNT series Falling Skies, and made an on-screen appearance in American Sniper as a Veteran Affairs Doctor who consults with Chris Kyle. Clotworthy also voiced the Black Knight, Zelgius, and Finn in Nintendo's mobile title, Fire Emblem Heroes.

Twelve years after the release of StarCraft, Clotworthy reprised his role as Raynor in StarCraft II: Wings of Liberty. The storyline of Wings of Liberty focuses primarily on the Terrans and Raynor in particular, with Raynor taking the role of main character. A review of Wings of Liberty on ITP.net stated that Raynor was "voiced to perfection" by Clotworthy and he was selected as the winner of "GotY Awards 2010 – Best Voice Acting" by reactiontime.co.uk. Clotworthy returned to the role with the expansions StarCraft II: Heart of the Swarm and StarCraft II: Legacy of the Void, as well as Blizzard Entertainment's multiplayer online battle arena Heroes of the Storm.