Patrick John Flueger is an American actor, first known for a principal role as Shawn Farrell in the television series The 4400. He currently appears in a lead role on Chicago P.D., playing Adam Ruzek.

The 4400 is a science fiction television series produced by CBS Paramount Network Television in association with BSkyB, Renegade 83, and American Zoetrope for USA Network in the United States and Sky One in the United Kingdom. It was created and written by Scott Peters and René Echevarria, and it starred Joel Gretsch and Jacqueline McKenzie. The series ran for four seasons from July 11, 2004, to September 16, 2007.