The windowpane oyster (Placuna placenta) is a bivalve marine mollusk in the family of Placunidae.

Distribution extends from the shallows of the Gulf of Aden to around the Philippines, where it is abundant in the eponymous province of Capiz.

The mollusks are found in muddy or sandy shores, in bays, coves and lagoons to a depth of about 100 m (330 ft).

In the Philippines, fisheries are now regulated through permits, quotas, size limits and protected habitats.

Fertilization is external and larvae are free-swimming like plankton for 14 days or attached to surfaces via byssal thread during metamorphosis, eventually settling on the bottom.