Riley Sager is a bestselling American author known for his gripping psychological thrillers and modern take on suspense fiction. Writing under the pen name Riley Sager, he was born Todd Ritter and worked for years in book publicity and marketing, giving him deep insight into storytelling and what resonates with readers. Before turning to full‑time writing, he held positions at major publishing houses, where he helped promote many bestselling authors.

Sager burst onto the thriller scene with his debut novel Final Girls (2017), a meta‑horror mystery that became a bestseller and established his reputation for clever plotting and homage to classic genre tropes. Since then, he has published a string of successful thrillers, including The Last Time I Lied, Lock Every Door, Home Before Dark, and The Only One Left. His novels often blend tense atmosphere, unreliable narrators, and twisty resolutions, appealing to fans of psychological suspense and contemporary mystery.