He plays Frank Reynolds on the FXX sitcom It’s Always Sunny in Philadelphia (2006-present).
DeVito is known for his film roles in One Flew Over the
Cuckoo’s Nest (1975),
Terms of Endearment (1983), Head Office (1985),
Ruthless People (1986), Throw Momma from the Train

(1987), Twins (1988),
The War of the Roses (1989), Batman Returns (1992), Jack the Bear (1993), Junior (1994),
DeVito also owned Jersey Television, which produced the Comedy Central series Reno 911!
De Vito and wife Rhea Perlman starred together in his 1996 film Matilda, based on Roald Dahl’s children’s novel.
DeVito was also one of the producers nominated for an
Academy Award for Best Picture for Erin Brockovich (2000).
From 2012 to 2013, DeVito played Willie Clark in the West End revival of Neil Simon’s The Sunshine Boys.
He made his Broadway debut as Gregory Solomon in the revival of Arthur Miller’s The Price (2017)
, earning a Tony Award nomination for his performance.
He returned to Broadway in the Theresa Rebeck play I Need That (2023).