Egertonia (named after paleontologist Sir Philip Grey Egerton, 10th Baronet) is an extinct genus of prehistoric marine and estuarine ray-finned fish known from the Late Cretaceous to the middle Eocene.

It was a member of the Phyllodontidae, an extinct family of elopomorph fish with crushing tooth plates, which are the primary remains found of the genus.

These formations are suggestive of a fluvial-estuarine environment with frequent marine intrusions.

Notably, despite Egertonia expanding its range to the Northern Hemisphere during the Cenozoic, both of these early localities are Gondwanan in origin.

[3][4] As with several other members of its family, Egertonia survived the Cretaceous-Paleogene extinction event and it became more widespread during the Cenozoic, when the type species E. isodonta appears.