The Pima are a group of American Indians

Indigenous peoples of the Americas

The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...

 living in an area consisting of what is now central and southern Arizona

Southern Arizona

Southern Arizona is a region of the United States comprising the southernmost portion of the State of Arizona. It sometimes goes by the name Baja Arizona, which means "Lower Arizona" in Spanish.- Geography :...

. The long name, "Akimel O'odham", means "river people". They are closely related to the Tohono O'odham

Tohono O'odham

The Tohono O'odham are a group of Native American people who reside primarily in the Sonoran Desert of the southeastern Arizona and northwest Mexico...

 (meaning "desert people") and the Hia C-ed O'odham

Hia C-ed O'odham

The Hia C-eḍ O'odham , also known as Areneños, Sand Papagos, or Sand Pimas are a Native American peoples whose traditional homeland lies between the Ajo Range, the Gila River, the Colorado River, and the Gulf of California...

. They are also closely related to another river people, the Sobaipuri

Sobaipuri

The Sobaipuri are one of many indigenous groups occupying Sonora at the time Europeans first entered the American Southwest. They were a Piman group who occupied southern Arizona and northern Sonora in the 15th-19th centuries...

, whose descendants still reside at San Xavier del Bac or Wa:k and in the Gila River communities. The short name, "Pima" is believed to have come from the phrase pi 'añi mac or pi mac, meaning "I don't know," used repeatedly in their initial meeting with Europeans.
The Pima Indians first called themselves Otama until the first account of interaction with non-Native Americans was recorded.