Monomorium bidentatum is a species of ant in the subfamily Myrmicinae.

It is endemic to two South American countries, Chile and Argentina.

The general color is dark brown, with the mandibles, antennae and legs slightly lighter.

[4] Both species were originally described by Gustav Mayr under genus Monomorium.

[2] However, Antichthonidris was synonymized with Monomorium in 2001, so that this genus is no longer valid, and the two species are again known under their original name.