The NBC comedy features Perry as an "irreverent yet charming" sportscaster who goes to therapy sessions in an attempt to move on from a loss.
The Playboy Club star will be the female lead on the sitcom and will appear as the leader of the support group that Perry's sportscaster goes to, according to TV Line.
Terra Nova star Allison Miller - who played Skye on Fox's sci-fi drama - joined the cast of Go On last week.
Benanti played the character of Carol-Lynne on The Playboy Club before it got axed by NBC.
She has featured in several episodes of Starved in 2005 as well as recurring roles on Eli Stone and more recently Law & Order: Special Victims Unit.
Benanti has also had guest spots on the US version of Life on Mars and The Big C.
Watch Benanti on The Playboy Club below: