Eoacmaea is a genus of sea snails or true limpets, marine gastropod mollusks in the subclass Patellogastropoda, the true limpets.

[2] Eoacmaea is the only genus in the family Eoacmaeidae, belonging to the superfamily Lottioidea.

The generic name Eoacmaea is composed from the Eo that mean "early"[1] in Greek and Acmaea,[1] that is the genus of gastropod in family Lottiidae.

The family Eoacmaeidae was established by Nakano & Ozawa (2007)[1] for the genus Eoacmaea.

A cladogram based on sequences of mitochondrial 12S ribosomal RNA, 16S ribosomal RNA and cytochrome-c oxidase I (COI) genes showing phylogenic relations of Patellogastropoda by Nakano & Ozawa (2007)[1] and superfamilies based on World Register of Marine Species:[2] Lottiidae (including Acmaea and Niveotectura) Pectinodontidae Lepetidae Nacellidae Patellidae Eoacmaeidae - only one genus Eoacmaea Eoacmaea is the most basal group within Patellogastropoda[1] and Eoacmaea have diversified from other Patellogastropoda in Tethys Ocean in Triassic or Jurassic about 203 million years ago (limits are from 143 to 279 million years ago).