The City and County of Denver () is the consolidated city and county that is the capital and most populous city of the U.S. State of Colorado. The population was 715,522 at the 2020 United States census, a 19.22% increase since the 2010 United States census. Denver is the 19th-most populous city in the United States and the fifth most populous state capital. Denver is the principal city of the Denver–Aurora–Lakewood, CO Metropolitan Statistical Area and the first city of the Front Range Urban Corridor. Denver is located in the South Platte River Valley on the western edge of the High Plains just east of the Front Range of the Rocky Mountains. The Denver downtown district is immediately east of the confluence of Cherry Creek and the South Platte River, approximately 12 mi (19 km) east of the foothills of the Rocky Mountains. Denver is named after James W. Denver, a governor of the Kansas Territory. It is nicknamed the Mile High City because its official elevation is exactly one mile (5280 feet or 1609.344 meters) above sea level. The 105th meridian west of Greenwich, the longitudinal reference for the Mountain Time Zone, passes directly through Denver Union Station. Denver is ranked as a Beta world city by the Globalization and World Cities Research Network. The 10-county Denver-Aurora-Lakewood, CO Metropolitan Statistical Area had a population of 2,963,821 at the 2020 United States Census, making it the 19th most populous U.S. metropolitan statistical area. The 12-county Denver-Aurora, CO Combined Statistical Area had a population of 3,623,560 at the 2020 United States Census, making it the 17th most populous U.S. primary statistical area. Denver is the most populous city of the 18-county Front Range Urban Corridor, an oblong urban region stretching across two states with a population of 5,055,344 at the 2020 United States Census. The Denver metropolitan area is the most populous metropolitan area within an 560-mile (900 km) radius and the second most populous city in the Mountain West after Phoenix, Arizona. In 2016, Denver was named the best place to live in the United States by U.S. News & World Report.

The City of Lakewood is the home rule municipality that is the most populous municipality in Jefferson County, Colorado, United States. The city population was 155,984 at the 2020 U.S. Census making Lakewood is the fifth most populous city in Colorado and the 167th most populous city in the United States. Lying immediately west of Denver, Lakewood is a principal city of the Denver–Aurora–Lakewood, CO Metropolitan Statistical Area and a major city of the Front Range Urban Corridor.

The City of Golden is a home rule municipality and county seat of Jefferson County, Colorado, United States. Golden lies along Clear Creek at the base of the Front Range of the Rocky Mountains. Founded during the Pike's Peak Gold Rush on June 16, 1859, the mining camp was originally named Golden City in honor of Thomas L. Golden. Golden City served as the capital of the provisional Territory of Jefferson from 1860 to 1861, and capital of the official Territory of Colorado from 1862 to 1867. In 1867, the territorial capital was moved about 12 miles (19 km) east to Denver City. Golden is a part of the Denver–Aurora–Lakewood, CO Metropolitan Statistical Area. As of the 2010 census, the city population was 18,867.The Colorado School of Mines, offering programs in engineering and science, is located in Golden. Also there are the National Renewable Energy Laboratory, National Earthquake Information Center, Coors Brewing Company, CoorsTek, Boston Market, Spyderco, Software Bisque, American Mountaineering Center, and Colorado Railroad Museum. It is the birthplace of the Jolly Rancher, a candy bought out by the Hershey Foods Corporation, and home to Yeti Cycles. Famous western showman William F. "Buffalo Bill" Cody is buried nearby on Lookout Mountain.

The City of Aurora (, ) is a home rule municipality located in Arapahoe, Adams, and Douglas counties, Colorado, United States. The city's population was 386,261 at the 2020 United States Census with 336,035 residing in Arapahoe County, 47,720 residing in Adams County, and 2,506 residing in Douglas County. Aurora is the third most populous city in the State of Colorado and the 51st most populous city in the United States. Aurora is a principal city of the Denver–Aurora–Lakewood Metropolitan Statistical Area (MSA) and a major city of the Front Range Urban Corridor.