Marc Laidlaw

Marc Laidlaw is an American writer. Between 1997 and 2016, he was a writer for the video game company Valve, where he worked on the Half-Life and Portal series.

Before joining Valve, Laidlaw was a novelist working in fantasy and horror. In 1996 he won the International Horror Guild Award for his novel The 37th Mandala. In 2025, Laidlaw's 1983 short story "400 Boys" was adapted as an episode of the Netflix series Love, Death& Robots.