Filmmaker Mike Flanagan is in talks to serve as an executive producer on Amazon MGM Studios' TV adaptation of Warhammer 40,000, the sci-fi war-game property being developed as a passion project for and starring Henry Cavill. It is not yet confirmed whether Flanagan, known for horror hits such as The Haunting of Hill House and Doctor Sleep, would also showrun the series, but his involvement would mark a significant creative addition to one of Amazon's most anticipated genre projects.

Amazon MGM Studios acquired global rights to Games Workshop's Warhammer 40,000 in December 2024, with Cavill set to executive produce and star. Flanagan already has an overall deal with the studio, under which his first project, an adaptation of Stephen King's Carrie, is due on Prime Video on 7 October 2026; he is also currently writing and directing The Exorcist: Martyrs for Blumhouse and Universal. Vertigo Entertainment's Roy Lee and Natalie Viscuso, who helped Cavill secure the IP before bringing it to Amazon, remain attached as executive producers alongside Games Workshop's Andy Smillie and Max Bottrill.