Tracy S. Letts, born on 4 July 1965, is a screenwriter, dramatist, and actor from the United States. He won the Pulitzer Prize for Drama and the Tony Award for Best Play for his production of August: Osage County (2007), as well as the Tony Award for Best Actor in a Play for his role as George in the revival of Who's Afraid of Virginia Woolf? (2013). He is well renowned for his role as Andrew Lockhart in seasons 3 and 4 of Showtime's Homeland, for which he received two Screen Actors Guild Awards as a part of the ensemble. Letts appeared in three critically praised films in 2017: The Lovers, Lady Bird, and The Post. Both of the later films were nominated for Academy Awards for Best Picture. Letts, for his work in Lady Bird, was nominated for a Screen Actors Guild Award for Outstanding Performance by a Cast in a Motion Picture.

He played Henry Ford II in James Mangold's Ford v Ferrari in 2019. Letts authored the screenplays for three films based on his plays: Bug, Killer Joe, and August: Osage County, all directed by William Friedkin, and August: Osage County, directed by John Wells. Superior Donuts, his 2009 play, was transformed into a television series of the same name. His first screenplay, The Woman in the Window, which was not adapted from his own work, was released on14 May 2021, based on A.J.Finn's 2018 novel of the same name. Letts began his acting career in the 1990s and appeared in Television shows such as Prison Break, The District, Strong Medicine, Profiler, Judging Amy, The Drew Carey Show, Seinfeld, Early Edition, and Home Improvement.

Letts has written a total of 10 plays. On 28 June 2007, his most renowned film, August: Osage County, opened at Chicago's Steppenwolf Theatre. Letts has written scripts for three feature films based on his plays: Bug (directed by William Friedkin), Killer Joe (also directed by Friedkin), and August: Osage County (also directed by Friedkin) (directed by John Wells). He also authored the script for Amy Adams's 2021 Netflix feature film The Woman in the Window, which is based on A.J. Finn's eponymous psychological thriller.