Jeffrey Warren "Jeff" Daniels (born February 19, 1955) is an American actor, musician and playwright. He founded a non-profit theatre company, the Purple Rose Theatre Company, in his home state of Michigan. He has performed in a number of stage productions, both on and off-Broadway. He has been nominated for the Tony Award as Best Actor for the Broadway play God of Carnage (2009), along with his other three cast-mates. He has had a thriving film career, from his debut in 1981 in Ragtime, through State of Play in 2009. For his film work, he has received three Golden Globe Award nominations, including as Best Performance by an Actor in a Motion Picture - Comedy/Musical for Woody Allen's The Purple Rose of Cairo (1985) (hence the name of his theatre company). He has also received nominations by the Screen Actors Guild, Satellite Awards, and several for his work in The Squid and the Whale (London Critics Circle Awards, Independent Spirit Awards, Chlotrudis Awards and Gotham Awards).

Daniels was born in Athens, Georgia and grew up in Chelsea, Michigan, where his father, Robert Lee Daniels, still owns the local lumber yard. He was raised Methodist. Daniels attended Central Michigan University and participated in their theater program. In the Summer of 1976 he attended the Eastern Michigan University (EMU) drama school to participate in a special Bi-Centenniel Repertory programme where he performed in Hot L Baltimore and three other plays performed in repertoire. Marshall Mason was the guest director at EMU and he invited Jeff to come to New York to work at the Circle Repertory Theatre where he performed in The Fifth of July by Lanford Wilson in the 1977-1978 season. He also performed in New York in The Shortchanged Review (1979) at Second Stage Theatre. It was the first show of the inaugural season for Second Stage Theatre.

Daniels has starred in a number of New York productions, on and off Broadway. On Broadway, he has appeared in Lanford Wilson's Redwood Curtain, A. R. Gurney's The Golden Age and Wilson's Fifth of July, for which he won a Drama Desk Award for Best Supporting Actor. Off-Broadway, he received a Drama Desk nomination for Wilson's Lemon Sky, and an Obie Award for his performance in the Circle Repertory Company production of Johnny Got His Gun. He returned to the stage in 2009, appearing in Broadway's God of Carnage with Marcia Gay Harden, Hope Davis and James Gandolfini.