Megathous nigerrimus is a species of click beetles in the family Elateridae.

[5] Megathous nigerrimus can reach a body length of about 20 mm (0.79 in).

These click beetles are entirely black, moderately shiny, including antennae and legs.

Frons is arcuate anteriorly with margin simple on level with clypeus at middle.

[6] The larvae develop as predators in decayed trunks and stumps of different tree species.