Sphaerium rhomboideum

{{Short description|Species of bivalve}}

{{Speciesbox

| image = Sphaerium rhomboideum.jpg

| taxon = Sphaerium rhomboideum

| authority = (Say, 1822)Say, 1822, Jour. Acad. Nat. Sci.: 380

| display_parents = 3

| synonyms =

• Cyclas rhomboidea Say, 1822
• Cyclas elegans Adams, 1840Adams, 1840, Proc. Boston Soc. Nat. Hist.: pl. 3, fig. 11

}}

Sphaerium rhomboideum, the rhomboid fingernailclam, is a species of freshwater clams in the family Sphaeriidae. It is found in North America.