MainEdit

• Darby Stanchfield as Nina Locke, the matriarch of the Locke family
• Connor Jessup as Tyler Locke, the eldest son of the Locke family
• Emilia Jones as Kinsey Locke, the middle child and only daughter of the Locke family
• Jackson Robert Scott as Bode Locke, the youngest son of the Locke family
• Petrice Jones as Scot Cavendish, a British student filmmaker at Matheson Academy, and a love interest of Kinsey's
• Laysla De Oliveira as Echo/Dodge,^[a] the "well lady" of Keyhouse, who is revealed to be a demonic entity
• Griffin Gluck as Gabe,^[b] a new student at Matheson Academy, and a love interest of Kinsey's

RecurringEdit

• Bill Heck as Rendell Locke, the patriarch of the Locke family and Nina's deceased husband
• Aaron Ashmore as Duncan Locke, Rendell's younger brother
• Sherri Saum as Ellie Whedon, an old friend of Rendell's who dated Rendell's best friend Lucas back in high school and a physical education teacher at Matheson Academy
• Thomas Mitchell Barnet as Sam Lesser, Rendell's student who shoots and kills Rendell
• Kevin Alves as Javi, Tyler's friend, who is on the hockey team with him at Matheson Academy
• Genevieve Kang as Jackie Veda, a girl on whom Tyler has a crush
• Hallea Jones as Eden Hawkins, Jackie's best friend and rival to Kinsey
• Kolton Stewart as Brinker Martin, Javi's friend
• Asha Bromfield as Zadie Wells, one of Scot's friends
• Jesse Camacho as Doug Brazelle, one of Scot's friends
• Eric Graise as Logan Calloway, a disabled student at Matheson Academy
• Felix Mallard as Lucas Caravaggio,^[c] Rendell's best friend from high school and Ellie's first love
• Steven Williams as Joe Ridgeway, the dean of 11th grade and Tyler's English teacher at Matheson Academy
• Coby Bird as Rufus Whedon, Ellie's adopted son and the groundskeeper of Keyhouse; he is fascinated by the army and weapons.