Izzard will play Abbott Thrush, an upper-class English barrister brought in to fight Lockhart/Gardner in a libel case that finds its way into British court.
"Eddie Izzard has the one thing we're always looking for: enormous talent with both comedy and drama," co-creators and executive producers Robert and Michelle King said. "We couldn't be more excited to have him on the show!"
The Kings are already leaving the door open for Izzard to reprise his role in the future. "At this point he's only in one episode. But folks do have a way of returning...," they said.
Season 3 of The Good Wife premieres on Sunday, Sept. 25 at 9/8c on CBS.