Isaac Liev Schreiber (; born October 4, 1967) is an American actor, director, screenwriter, and producer. He became known during the late 1990s and early 2000s, having appeared in several independent films, and later mainstream Hollywood films, including the Scream trilogy of horror films, Ransom (1996), Phantoms (1998), The Sum of All Fears (2002), The Omen (2006), X-Men Origins: Wolverine (2009), Taking Woodstock (2009), Salt (2010), Goon (2011), Pawn Sacrifice (2014), and Spotlight (2015). He later became known through a younger generation of audiences for his work in My Little Pony: The Movie (2017) and Spider-Man: Into the Spider-Verse (2018).
Schreiber is also a stage actor, having performed in several Broadway productions. In 2005, he won the Tony Award for Best Featured Actor in a Play for his performance in the play Glengarry Glen Ross. That year, he made his debut as a film director and writer with Everything Is Illuminated (2005), based on the novel of the same name. Schreiber has had further success in the television world, notably portraying the eponymous protagonist of the Showtime drama series Ray Donovan (2013–present); the role has earned him five Golden Globe Award nominations and three Primetime Emmy Award nominations. He also narrates the HBO series 24/7, as well as various PBS programs.