Dondice occidentalis is a species of sea slug, an aeolid nudibranch, a marine gastropod mollusc in the family Myrrhinidae.

[4] Distribution of Dondice occidentalis includes Florida, Mexico, Belize, Costa Rica, Colombia, Venezuela, Curaçao, Bonaire, Venezuela, Bermudas, Bahamas, Cayman Islands, Jamaica, Turks and Caicos, Grenada, Sint Maarten, Martinique, Trinidad, Brazil and Panama.

Background color is translucent gray with a yellow or orange median line of variable width, running from the head to the anterior end, between the rhinophores.

There is sometimes present a white or blue broken line down the dorsal mid-line from behind the rhinophores to the posterior end of the body.

Cerata are translucent gray, often with large blue or white bands covering the upper two-thirds of each ceras.