Thaumatomyrmex is a Neotropical genus of ants in the subfamily Ponerinae, found from Mexico to Brazil.

The genus was established by Mayr in 1877 to house the single species Thaumatomyrmex mutilatus, discovered in Brazil.

[5] Thaumatomyrmex is found only in the Neotropics, from Mexico to Brazil (including Cuba and other Caribbean islands).

The genus was once thought to be rare, but with better sampling techniques, the ants are now found more frequently.

Thaumatomyrmex use their long mandibles to hold the polyxenids before immobilizing them by stinging, and then stripping the prey from their protective setae.