See text Unio is a genus of medium-sized freshwater mussels, aquatic bivalve mollusks in the family Unionidae, the river mussels.

They are found throughout Europe, Africa, and the Middle East, with some species introduced to East Asia.

Fossil species are also known from the Jurassic of North America.

[1] Unio is the type genus of the family Unionidae.

Species in the genus Unio include:[1][2]