Ipai, also known as 'Iipai or Northern Diegueño, is the Native American language spoken by the Kumeyaay people of central San Diego County, California.

Professor Leanne Hinton suggested a conservative estimate of 25 surviving Ipai speakers.

Confusingly, Kumeyaay is commonly used as a designation both for the central language in this family and for the Ipai-Kumeyaay-Tipai people as a whole.

Published documentation for the Ipai language includes reference and teaching grammars, a dictionary, and several texts (cf.

A language revitalization effort for Santa Ysabel Iipaay Aa is underway.