Ephydrolithus is a Neotropical genus of water scavenger beetle in the family Hydrophilidae represented by five described species known from Brazil.

[2] It belongs in the subfamily Acidocerinae and contains three described species from Brazil (Bahía, Minas Gerais).

[1][2] Small beetles (1.8–3.3 mm), yellowish-brown to dark brown in coloration, with relatively short maxillary palps.

A complete diagnosis was presented by Girón and Short.

[1][2] According to Girón and Short "All known species are exclusively associated with rock seepages".