Tempe ( /tɛmˈpiː/, US dict: tem-ˈpē;Oidbaḍ in Pima), also known as Hayden's Ferry during the territorial times of Arizona, is a city in Maricopa County, Arizona, USA, with the Census Bureau reporting a 2010 population of 161,719. The city is named after the Vale of Tempe in Greece. Tempe is located in the East Valley section of metropolitan Phoenix; it is bordered by Phoenix and Guadalupe on the west, Scottsdale on the north, Chandler on the south, and Mesa on the east. Tempe is the location of US Airways Group's corporate headquarters, and of Arizona State University's oldest and largest "Tempe" campus.

The Hohokam initially lived in this area and built canals to support their agriculture. They abandoned their settlements during the 15th century, with a few individuals and families remaining nearby.

Fort McDowell was established approximately 25 miles northeast of present downtown Tempe on the upper Salt River in 1865 allowing for new towns to be built further down the Salt River. US military service members and Hispanic workers were hired to grow food and animal feed to supply the fort, and less than a year later, had set up small camps near the river that were the first permanent communities in the Valley after the fall of the Hohokam. (Phoenix was settled shortly afterward, by 1867-68.) The two settlements were 'Hayden's Ferry', named after a ferry service operated by Charles T. Hayden, and 'San Pablo', and were located west and east of Hayden Butte respectively. The ferry became the key river crossing in the area. The Tempe Irrigating Canal Company was soon established by William Kirkland and James McKinney to provide water for alfalfa, wheat, barley, oats, and cotton.

Arizona (ⁱ/ɛrɪˈzoʊnə/; /ærɪˈzoʊnə/) (Navajo: Hoozdo Hahoodzo; O'odham: Alĭ ṣonak) is a state of the United States, located in the southwestern region of the country. Arizona is also part of the Western United States and of the Mountain West states. Arizona is the sixth most extensive and the 16th most populous of the 50 states. Its capital and largest city is Phoenix. The second largest city is Tucson, followed in population by eight cities of the Phoenix metropolitan area: Mesa, Chandler, Glendale, Scottsdale, Gilbert, Tempe, Peoria, and Surprise.

Arizona is the 48th state and last of the contiguous states to be admitted to the Union, and it achieved statehood on February 14, 1912. Arizona is noted for its desert climate in its southern half, where there are very hot summers and quite mild winters. The northern half of Arizona also features forests of pine, Douglas fir, and spruce trees, a very large, high plateau (the Colorado Plateau) and some mountain ranges—such as the San Francisco Mountains—as well as large, deep canyons, where there is much more moderate weather for three seasons of the year, plus significant snowfalls. There are ski resorts in the areas of Flagstaff and Alpine.