The City of Centennial is a Home Rule City located in Arapahoe County, Colorado, United States, and part of the Denver-Aurora metropolitan area. The city had a total population of 100,377 in 2010 census. Centennial is the tenth-most populous municipality in the state of Colorado and its 2001 incorporation was the largest in U.S. history. Centennial is ranked as the 15th safest city in the country.