Cirsochilus is an extinct genus of sea snails, marine gastropod molluscs in the family Colloniidae. Fossils of the genus date to between the Cretaceous and the Quaternary periods, and are found globally.
Members of the genus have a thickened inner lip, sharp edge, and a pearly shell.
Cirsochilus was first described by Maurice Cossmann in 1888 as a subgenus of Collonia. It was raised to genus level by Jean-Michel Pacaud and Jacques Le Renard in 1995.
Fossils of the genus date to between the Cretaceous period and Quaternary period, and have been found in the Americas, Europe, Asia and Oceania.
Species within the genus Cirsochilus include: