Neotrigonia is a genus of living saltwater clams, in the family Trigoniidae, which otherwise consists only of fossil genera.

At that time it was assigned to the fossil genus Trigonia.

In 1802, however, François Péron discovered a living species in waters off the coast of Tasmania.

In 1804, Lamarck named that species Trigonia margaritacea, and Cossmann renamed the genus Neotrigonia in 1912.

Today, eight living species are known to exist, all of which are found off the coast of Australia and Tasmania.