Thanatotheristes (meaning "reaper of death" according to the original authors; literally, "death harvester" in Greek: Θάνατος, romanized: Thánatos, "Death" and θεριστής, romanized: theristḗs, "harvester") is a genus of tyrannosaurid dinosaur from the Late Cretaceous of Laramidia, approximately 80.1-79.5 Ma. Thanatotheristes contains only one species, T. degrootorum. Fossils of this taxon are found in the Foremost Formation of Alberta, Canada, coexisting with medium-sized ceratopsids like Xenoceratops foremostensis and small pachycephalosaurids like Colepiocephale lambei.