Production on the fresh episodes is to begin early next year. Both shows will have 12-episode seasons, David Nevins, the cable network's president, announced Wednesday.
"Both Ray Donovan and Masters of Sex are quintessentially Showtime: bold, provocative, premium television with production values at the top of the food chain," Nevins said in a statement. "These acclaimed shows are filled with complex and interesting characters and settings that will no doubt give audiences compelling television to invest in for seasons to come."
"Set in the sprawling mecca of the rich and famous, Ray Donovan stars Golden Globe and Emmy nominee Liev Schreiber as L.A.'s best professional fixer, the man called in to make the city's celebrities, superstar athletes, and business moguls' most complicated and combustible situations go away," a synopsis said.
Masters of Sex casts Michael Sheen and Lizzy Caplan as real-life pioneers of human sexuality, William Masters and Virginia Johnson. The show chronicles "their unusual lives, romance and pop-culture trajectory," a synopsis said.