Robert Lyle Knepper (born July 8, 1959 in Fremont, Ohio) is an American actor. He's earned critical acclaim for his roles in film and television, often cast as memorable villains. He's perhaps best known for playing Breakout Character Theodore "T-Bag" Bagwell in the FOX drama series Prison Break from 2005 to 2009.
He has also appeared in films such as Good Night, and Good Luck., Hitman, and Transporter 3. Knepper joined the cast of Heroes for its fourth and final season as Samuel Sullivan from 2009 to 2010, and he played Sid Rothman in the neo-noir television series Mob City in 2013. He starred as Antonius in The Hunger Games: Mockingjay Part 1 and Part 2.
- Embarrassing Last Name: His last name means the verb 'Fuck'/'Fucks' in Danish (as in 'Robert fucks').
- Star-Making Role: His role as T-Bag in Prison Break; the character became an Ensemble Dark Horse and Breakout Character, and was the only character to appear in another show - Breakout Kings.
- Typecasting: He's usually cast as charismatic and sneaky villains.
- Phantoms as Agent Wilson
- Wild Thing as the Wild Thing
- Good Night, and Good Luck. as Don Surine
- Hostage as Will Bechler
- Hitman as Yuri Marklov
- Transporter 3 as Johnson
- R.I.P.D. as Stanley Nawlicki
- Percy Jackson and the Olympians as Kronos
- The Hunger Games as Antonius
- Jack Reacher: Never Go Back as General Harkness
- The Twilight Zone (1985) as Alonzo
- Star Trek: The Next Generation as Wyatt Miller
- Murder, She Wrote as Charles George Drexler/Owen McLaglen/Robbie Dorow
- Law & Order as Daniel "Igor" Smith
- ER as Keith Reynolds
- Star Trek: Voyager as Gaul
- La Femme Nikita as Henry Collins
- Law & Order: Criminal Intent as Dr. Peter Kelmer
- The West Wing as Morgan Ross
- CSI: Miami as Freddy Coleman
- Carnivàle as Tommy Dolan
- Prison Break as Theodore "T-Bag" Bagwell
- Heroes as Samuel Sullivan
- Stargate Universe as Simeon
- Criminal Minds as Rhett Walden
- Hawaii Five-0 as Internal Affairs Officer Coughlin
- Cult as Roger Reeves/Billy Grimm
- The Blacklist as The Courier
- Mob City as Sid Rothman
- Arrow as William Tockman / Clock King
- The Flash (2014) as William Tockman / Clock King
- Chicago Fire as Adrian Gish/Trenton Lamont
- Chicago P.D. as Adrian Gish/Trenton Lamont
- Texas Rising as Empresario Buckley
- NCIS as Benson Long
- iZombie as Angus McDonough