Flagstaff (Navajo: Kinłání) is a city located in northern Arizona, in the southwestern United States. As of the 2000 census, the city had a total population of 52,894. It is the county seat of Coconino County ^GR6, an important railroad town, and home to Lowell Observatory and Northern Arizona University.

The city's name commemorates a Ponderosa Pine tree that was made into a tall flagpole by members of a scouting party from Boston, Massachusetts on July 4, 1876 to celebrate the United States Centennial.

Flagstaff lies near the southwestern edge of the Colorado Plateau and along the western side of the largest contiguous ponderosa pine forest on earth at an elevation of around 7,000 ft (2,000 m). Flagstaff is located just south of the San Francisco Peaks, the highest mountain range in Arizona. Humphreys Peak, an ancient volcano and the highest point in Arizona at 12,633 ft (3,850 m), is located about 10 mi (16 km) north of Flagstaff in the San Francisco Peaks. Old Route 66 runs through downtown Flagstaff between Barstow, California and Albuquerque, New Mexico. Flagstaff is the notheren terminus of Interstate 17 which runs 145 mi (232 km) south to the city of Phoenix, Arizona. The town's name is mentioned in the lyrics to the song, "Route 66".

Besides winter snow skiing at the Arizona Snow Bowl west of Humphreys Peak, nearby tourist attractions include Walnut Canyon National Monument, Sunset Crater Volcano National Monument, Wupatki National Monument, Oak Creek Canyon, Barringer Crater (meteor crater), The Arboretum at Flagstaff, and the Museum of Northern Arizona. Grand Canyon National Park is 75 mi (120 km) north of Flagstaff along U.S. Route 180 while Glen Canyon National Recreation Area and Lake Powell are both about 135 mi (216 km) north along U.S. Route 89