Truncilla donaciformis

{{Short description|Species of bivalve}}

{{Speciesbox

| image = Truncilla donaciformis - Royal Ontario Museum - DSC00189.JPG

| status = G5

| status_system = TNC

| status_ref = {{cite web|url= https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.121170/Truncilla_donaciformis |title=Truncilla donaciformis|website=explorer.natureserve.org|publisher=NatureServe|author=NatureServe|access-date=24 November 2024}}

| genus = Truncilla

| species = donaciformis

| authority = I. Lea, 1828

}}

Truncilla donaciformis, the fawnsfoot, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae.

This species occurs in the Mississippi River drainage, Great Lakes region, Mobile basin, and Gulf Coast region in the United States, from South Dakota to Pennsylvania, south to Georgia and west to Texas as well as in southern Ontario, Canada.