Christian Michael Leonard Slater (born August 18, 1969) is an American actor. He made his film debut with a leading role in The Legend of Billie Jean (1985). He gained wider recognition for his breakout role as Jason "J.D." Dean, a sociopathic high school student, in the satire Heathers (1989). He received critical acclaim for playing the title role in the USA Network television series Mr. Robot (2015–2019): it earned him the 2016 Golden Globe Award for Best Supporting Actor – Series, Miniseries or Television Film, and additional nominations for that award in 2017 and 2018. For his role as Mulgarath in the fantasy series The Spiderwick Chronicles (2024), Slater received the Children's and Family Emmy Award for Outstanding Lead Performer.

In the 1990s, Slater starred in a number of big-budget films, including Young Guns II (1990), Robin Hood: Prince of Thieves (1991), Interview with the Vampire (1994), Broken Arrow (1996), and Hard Rain (1998) as well as cult films like Gleaming the Cube (1989), Pump Up the Volume (1990) and True Romance (1993). He has had roles in other notable films, including The Name of the Rose (1986), Tucker: The Man and His Dream (1988), Windtalkers (2002), Alone in the Dark (2005), Bobby (2006), He Was a Quiet Man(2007), Nymphomaniac (2013), The Wife (2017), We Can Be Heroes (2020), and Blink Twice (2024).