The City of Lakewood is a Home Rule Municipality that is the most populous city in Jefferson County, Colorado, United States. Lakewood is the fourth most populous city in the State of Colorado and the 164th most populous city in the United States. The United States Census Bureau estimates that in 2005 the population of the City of Lakewood was 140,671 (164th most populous U.S. city), the population of the Denver-Aurora Metropolitan Statistical Area was 2,359,994 (22nd most populous MSA), the population of the Denver-Aurora-Boulder Combined Statistical Area was 2,869,377 (15th most populous CSA), and the population of the Front Range Urban Corridor was 4,013,055.

The City of Lakewood was incorporated in 1969. At the time of incorporation the city population was already over 90,000, making Lakewood one of the largest cities, at the time of original incorporation, in the history of the United States.

The urban/suburban development of the community known as Lakewood was begun in 1889 by Charles Welch and W.A.H. Loveland, who platted a 13-block area along Colfax Avenue west of Denver in eastern Jefferson County. Loveland, the former president of the Colorado Central Railroad, retired to the new community of Lakewood after many years of living in nearby Golden.

Lakewood also houses the prestigious Lakewood High School, ranked number one in the state by Newsweek, and the only International Baccalaureate school in Jefferson County.