Fontigens is a genus of minute freshwater snails with an operculum, aquatic gastropod molluscs or micromolluscs in the family Hydrobiidae.

Species within the genus Fontigens include:^[1]

• Fontigens aldrichi (Call & Beecher, 1886)
• Fontigens antroecetes (Hubricht, 1940)
• Fontigens binneyana Hannibal, 1912
• Fontigens bottimeri (B.Walker, 1925)
• Fontigens cryptica Hubricht, 1963
• Fontigens holsingeri Hubricht, 1976 - Tapered cavesnail^{[citation needed]}
• Fontigens morrisoni Hershler, Holsinger & Hubricht, 1990
• Fontigens nickliniana (I.Lea, 1838)
• Fontigens orolibas Hubricht, 1957
• Fontigens proserpina (Hubricht, 1940)
• Fontigens tartarea Hubricht, 1963
• Fontigens turritella Hubricht, 1976 - Greenbrier cavesnail

^[1]