Lopha is a genus of marine bivalve molluscs in the family Ostreidae.

Lopha species have thick, strongly ribbed shells with unequal valves.

The margins of the valves have a characteristic zig-zag pattern.

The lower valve shows finger-like outgrowths, by which the molluscs adhere to the substrate.

These molluscs are stationary, epifaunal, suspension feeders, as they feed by filtering sea water to extract the nutrients.