Esmaeilius is a genus of toothcarps in the family Aphaniidae.

They are native to Iran and one species extending to Iraq.

Most species in the genus have very small distributions and all are seriously threatened.

The generic name pertains to Hamid Reza Esmaeili, for his contribution to the understanding of diversity within the family Aphaniidae.

[1][2] There are six valid species:[3]