
Fox will play a "very funny, very original character" said John Landgraf, president and general manager of FX Networks. Rescue Me stars Dennis Leary as Tommy Gavin, a troubled firefighter.
Fox's character, who uses a wheelchair, is the new boyfriend of Gavin's estranged wife Janet, played by Andrea Roth. Fox will make his appearance the fifth-season premiere set to air in Spring 2009.
Fox, 47, a friend of Leary's, was "really excited about the part," Landgraf said.
Fox retired from full time acting in 2000 due to his struggle with Parkinson's Disease. Since then he has appeared sporadically in guest roles.
The actor founded the Michael J. Fox Foundation for Parkinson's Research, which has raised millions of dollars. Fox has been a vocal supporter of stem cell research.