Diggs will appear as Dean Levine-Wilkins, who is described as a "meticulous and talented equity partner at Lockhart/Gardner who decides to throw in his lot with Diane Lockhart (Christine Baranski) and accompany her to Alicia (Julianna Margulies) and Cary’s (Matt Czuchry) company, Florrick/Agos."

"We couldn't be more excited to have Taye on the show," said executive producers/showrunners Robert and Michelle King in a statement. “We’ve been huge fans for years, and love his ability to play comedy and drama with equal ease.”

"The Good Wife" will return Sept. 21 at 9 PM ET on CBS; check local listings.

The hour-long series stars Julianna Margulies, Christine Baranski, Matt Czuchry, Archie Panjabi, Makenzie Vega, Alan Cumming, Matthew Goode and Zach Grenier.

It is produced by Scott Free Productions and King Size Productions in association with CBS Television Studios. Ridley Scott, Robert King, Michelle King, Brooke Kennedy, David W. Zucker, Ted Humphrey, Keith Eisner, Leonard Dick and Craig Turk are executive producers.