Alsophis is a genus of snakes in the subfamily Dipsadinae of the family Colubridae. Species in the genus Alsophis are among those snakes commonly called "racers". Alsophis species are endemic to the Lesser Antilles in the Caribbean. One species in the genus Alsophis, A. antiguae, is one of the world's rarest known snakes. Snakes of the genus Alsophis are small and rear-fanged, and they are considered harmless to humans. This genus contains nine described species which are recognized as being valid. Several species once included in this genus have been placed in the genera Borikenophis and Pseudalsophis.