The Final Destination 3 star will join Breaking Bad actor Aaron Paul and The Help actress Octavia Spencer, according to Variety.
Smashed centres on a relationship revolving around alcohol abuse, with Winstead and Paul playing the troubled couple. Their relationship begins to go sour when she decides to seek help for her drinking problem.
Spencer will take on the role of Winstead's character's sponsor, while Parks and Recreation actor Nick Offerman is currently in negotiations to play an assistant headmaster at the school where she teaches.
Off the Black's James Ponsoldt is directing from his own script, which was inspired by the Jack Lemmon and Lee Remick drama Days of Wine and Roses.
Winstead will next be seen in the prequel to John Carpenter's sci-fi horror classic The Thing released on October 14.
She is also currently attached to the comedy horror Abraham Lincoln: Vampire Hunter.
Watch the trailer for The Thing below: