Gammarus chevreuxi is a species of crustacean in the family Gammaridae. It was first described by Elsie Wilkins Sexton in 1913. The organism is very similar to Gammarus locusta, but there are certain constant characters which set it apart, for example, the antennae, the fourth side-plates and the third uropods. It is found in various places in England, such as the Severn Estuary, and in Portugal.