Megadytes is a genus of diving beetles in the family Dytiscidae.

They are found in slow-moving or static freshwater habitats in the Neotropics.

[1] The adult beetles measure about 1.65–4.75 cm (0.6–1.9 in) long depending on the exact species and the largest is also the largest in the family (together with certain Dytiscus).

[1][2][3] Following reclassification in 2024,[4] Megadytes now contains two described species:

This Dytiscidae-related article is a stub.