Exact terms of the deal have not been announced.
Muir, a 6-foot-2, 312 pound fifth-year player out of Kent State, comes to the Packers from the Indianapolis Colts. He's made 26 career starts with the Colts.
This is Muir's second run in Green Bay. Muir was originally signed as a non-drafted free agent with the Packers in 2007.