William Edward Fichtner (born November 27, 1956) is an American actor. He has appeared in a number of notable film and TV series. His best known movie roles are as Dellrayne in Hypnotic, Colonel Mulholland in 12 Strong, Mike in The Neighbor, General Adams in Independence Day: Resurgence, Eric Sacks in the live action remake of Teenage Mutant Ninja Turtles (2014), John Carlyle in Elysium, Butch Cavendish in The Lone Ranger, Guidry in Seal Team Six: The Raid on Osama Bin Laden, DA Frank Crenshaw in Date Night, Darren MacElroy in Blades of Glory, Captain Knauer in the 2005 remake of The Longest Yard, SFC Jeff Sanderson in Black Hawk Down, David "Sully" Sullivan in The Perfect Storm, Colonel Willie Sharp in Armageddon, Kent in Contact, Roger Van Zant in Heat, and William Wallace in Virtuosity. He was also the voice of the marriage counselor Dr. Wexler in Mr. & Mrs. Smith.

His best known TV roles are as Leo Nicoletti on ABC's The Company You Keep, Adam Janikowski on CBS's sitcom Mom, Carl Hickman on NBC's drama Crossing Lines, Alexander Mahone on FOX's drama Prison Break, Sheriff Tom Underlay in the ABC cult series Invasion, and Dr. Bruce Kellerman on ABC's medical drama MDs.