Isaac Liev Schreiber (/ˈliːɛv ˈʃraɪbər/ LEE-ev SHRY-bər; born October 4, 1967) is an American actor. He has received numerous accolades, including a Tony Award and nominations for nine Primetime Emmy Awards and five Golden Globe Awards.

Schreiber's early film roles include Mixed Nuts (1994), Party Girl (1995), The Daytrippers (1996), and Big Night (1996). He appeared in the first three Scream horror films (1996–2000), Ransom (1996), The Hurricane (1999), Hamlet (2000), Kate & Leopold (2001), The Manchurian Candidate (2004), The Painted Veil (2006), X-Men Origins: Wolverine (2009), Pawn Sacrifice (2014), and Spotlight (2015). He acted in the Wes Anderson films Isle of Dogs (2018), The French Dispatch (2021), and Asteroid City (2023). He made his directorial film debut with Everything Is Illuminated (2005).