Coconino County is located in the north central part of the U.S. state of Arizona. It is the second largest county by land area in the 48 continguous United States, behind San Bernardino County, California.

The county seat is Flagstaff. Coconino County contains Grand Canyon National Park, the Havasupai Nation, and parts of the Navajo Nation, Hualapai Nation, and Hopi Nation. It takes its name from Cosnino, a name applied to the Havasupai.