Kenneth Lonergan (New York, October 16, 1962) is an American playwright, screenwriter, and director, known for his realistic writing and his exploration of complex family dynamics and grief. His career began in theater, where he achieved success with plays such as *This Is Our Youth*, *Lobby Hero*, and *The Waverly Gallery*, the latter being a finalist for the Pulitzer Prize for Drama. He transitioned to film, writing the screenplay for films such as *Analyze This* and co-writing Martin Scorsese's *Gangs of New York*, for which he received an Academy Award nomination. His directorial debut, *You Can Count on Me* (2000), earned him another nomination for Best Screenplay. After the troubled production of *Margaret* (2011), he reached the pinnacle of his success with *Manchester by the Sea* (2016). The film earned him the Academy Award and the BAFTA Award for Best Original Screenplay, establishing him as one of the most important auteurs in contemporary American cinema for his ability to portray grief and guilt with profound humanity.