Madhouse is a 2004 American slasher film, directed and co-written by William Butler and starring Joshua Leonard, Jordan Ladd, Natasha Lyonne, Lance Henriksen, and Mark Holton. Its plot follows an intern who uncovers a series of murders at a rural psychiatric hospital.

Joshua Granville Leonard is an American actor, writer, and director, known for his role in The Blair Witch Project (1999). He has since starred in films such as Madhouse (2004), The Shaggy Dog (2006), Higher Ground (2011), The Motel Life (2012), Snake and Mongoose (2013), If I Stay (2014), The Town That Dreaded Sundown (2014), 6 Years (2015), and Unsane (2018).