Asteroceras (from Ancient Greek ἀστήρ (astḗr), meaning "star", and κέρας (kéras), meaning "horn") is an extinct genus of cephalopod belonging to the Ammonite subclass. These fast-moving nektonic carnivores lived during the Triassic and Jurassic periods (from 205.6 to 189.6 Ma).

Asteroceras fossils may be found in the Jurassic marine strata of Canada, China, Germany, Hong Kong, Hungary, Peru, and Turkey, in the Triassic of United States and at Lyme Regis in the Asteroceras obtusum zone of Upper Sinemurian age.