Macrarene diegensis is a fossil species of small sea snail, a marine gastropod mollusk in the family Liotiidae.

The narrowly umbilicated shell contains 4 whorls with distinct sutures and a projecting peripheral keel.

The oblique aperture is circular.

This fossil species shows some similarities with Macrarene coronadoensis and Macrarene californica.

It is found in the San Diego Formation, California, and dates from the Pliocene.