The sitcom stars Amanda Peet as a recently-divorced mother who falls for her new contractor, played by David Walton.
Boston Legal actor Miller will play Bob, the uncouth boss of Peet's Alex, according to TV Guide.
The veteran TV star recently appeared in episodes of Curb Your Enthusiasm and Lifetime's short-lived drama The Protector.
Damages actress Marcia Gay Harden also recently signed up for a guest role on Bent.
The series, from Scrubs writer Tad Quill, will premiere on NBC in 2012.
> Jeffrey Tambor joins Bent pilot
Watch a trailer for Bent below: