It is found on the seabed in the tropical eastern Pacific Ocean including Mexico, Panama, Ecuador and the Galápagos Islands.

Tripneustes depressus is the largest sea urchin species in the Galápagos Islands with a mean diameter of 11.5 cm (4.5 in).

T. ventricosus is found in the Caribbean and may have been separated from T. depressus by the closing of the land bridge between North and South America.

[5] Tripneustes depressus is found in the tropical eastern Pacific Ocean, occurring in Mexico, on the western coast of Central America, in Panama, in Ecuador and around the Galápagos Islands.

Red filamentous algae is the main dietary constituent but pieces of sponge and other invertebrates have been found among its stomach contents.