One Corpse Too Many is a medieval mystery novel set in the summer of 1138 by Ellis Peters. It is the second novel in the Cadfael Chronicles, first published in 1979.

Edith Mary Pargeter, also known by her pen name Ellis Peters, was an English author of works in many categories, especially history and historical fiction, and was also honoured for her translations of Czech classics. She is probably best known for her murder mysteries, both historical and modern, and especially for her medieval detective series The Cadfael Chronicles.