Opecoelidae is a family of trematodes.

It is the largest digenean family with over 90 genera and nearly 900 species, almost solely found in marine and freshwater teleost fishes.

[2] It was considered by Bray et al. to belong in the superfamily Opecoeloidea Ozaki, 1925 or the Brachycladioidea Odhner, 1905.

[2] Family Opecoelidae