Varunidae is a superfamily of thoracotrematan crabs. The delimitation of this family, part of the taxonomically confusing Grapsoidea, are undergoing revision. For long, they were placed at the rank of subfamily in the Grapsidae, but they appear to be closest to Macropthalmus and the Mictyridae, which are usually placed in the Ocypodoidea. It may thus be better to merge the latter superfamily with the Grapsoidea, retaining the latter name as it is older.
That nonwithstanding, the revision of the Grapsoidea (in the narrow, apparently paraphyletic sense) is not fully completed, as many taxa remain to be restudied. Already, several former Grapsidae genera have been moved to the Varunidae, and others are tentatively placed here pending detailed study. Among the most notheworthy of these is the Chinese Mitten Crab, Eriocheir sinensis.