Kyle Gallner (born October 22, 1986) is an American actor. He began acting in 2000, earning recognition for playing Bart Allen in the superhero series Smallville (2004–2009), Cassidy "Beaver" Casablancas in the mystery drama series Veronica Mars (2005–2006), and Reed Garrett in the police drama series CSI: NY (2006–2010).

Gallner was established as a scream king in the 2010s, starring in the horror films The Haunting in Connecticut, Jennifer's Body (both 2009), the Nightmare on Elm Street remake (2010), Red State (2011), Scream, Smile (both 2022) and its sequel Smile 2 (2024). His other films include Dear White People, American Sniper (both 2014), Dinner In America (2020), The Passenger, and Strange Darling (both 2023).