Insidious: Chapter 3 is a 2015 supernatural horror film written and directed by Leigh Whannell in his directorial debut. The film is a prequel to the first two films and the third installment in the Insidious franchise. The film stars Dermot Mulroney and Stefanie Scott, with Angus Sampson, Whannell, and Lin Shaye reprising their roles from the previous films.

Leigh Whannell is an Australian filmmaker and actor. He is best known for writing films directed by his friend James Wan, including Saw (2004), Dead Silence (2007), Insidious (2010), and Insidious: Chapter 2 (2013). Whannell made his directorial debut with Insidious: Chapter 3 (2015), and has since directed two more films, Upgrade (2018) and The Invisible Man (2020).