The Beast Must Die is a British thriller television series based on the novel of the same name by Nicholas Blake, adapted for television by Gaby Chiappe. It centres on a mother's grief for her son who was killed in a car accident. She takes matters into her own hands by posing as a novelist to ingratiate herself into the family of the man whom she believes to be responsible for her son's death.

The series premiered in the United Kingdom on BritBox on 27 May, 2021, and ran for one series of 5 episodes until 17 June, 2021. A second series was in development, titled A Sword In My Bones. ITVX, which absorbed Britbox, announced it would not proceed.