List of counties in Arizona in the context of "Maricopa County, Arizona"

Arizona is a landlocked state in the Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the northwest and California to the west, and shares an international border with the Mexican states of Sonora and Baja California to the south and southwest. Its capital and largest city is Phoenix, which is the most populous state capital and fifth-most populous city in the United States. Arizona is divided into 15 counties.

Arizona is the sixth-largest state by area and the 14th-most-populous of the 50 states. It is the 48th state and last of the contiguous states to be admitted to the Union, achieving statehood on February 14, 1912. Historically part of the territory of Alta California and Nuevo México in New Spain, it became part of independent Mexico in 1821. After being defeated in the Mexican–American War, Mexico ceded much of this territory to the United States in 1848, where the area became part of the New Mexico Territory. The southernmost portion of the state was acquired in 1853 through the Gadsden Purchase.

Grand Canyon National Park is a national park of the United States located in northwestern Arizona, the 15th site to have been named as a national park. The park's central feature is the Grand Canyon, a gorge of the Colorado River, which is often considered one of the Wonders of the World. The park, which covers 1,217,262 acres (1,901.972 sq mi; 4,926.08 km) of unincorporated area in Coconino and Mohave counties, received more than 4.9 million recreational visitors in 2024. The Grand Canyon was designated a World Heritage Site by UNESCO in 1979. The park celebrated its 100th anniversary on February 26, 2019.

Pima County (/ˈpiːmə/ PEE-mə) is a county in the south central region of the U.S. state of Arizona, one of 15 counties in the state. As of the 2020 census, the population was 1,043,433, making it Arizona's second-most populous county. The county seat is Tucson, where most of the population is centered. The county is named after the Pima Native Americans, also known as Akimel O'odham, who are indigenous to this area.

Pima County includes the entirety of the Tucson Metropolitan Statistical Area, and it is the third largest metropolitan area in the Southwestern United States.