Homalocephala Britton & Rose[1] Echinocactus is a genus of cacti in the subfamily Cactoideae.

[1] The generic name derives from the Ancient Greek ἐχῖνος (echînos), meaning "spiny," and cactus.

Members of the genus usually have heavy spination and relatively small flowers.

The fruits are copiously woolly, and this is one major distinction between Echinocactus and Ferocactus.

As of 2023, the genus includes 6 accepted species out of hundreds of plants having the name.