The City and County of Broomfield is a consolidated city and county in the U.S. state of Colorado. The population was 55,889 at the 2010 United States Census.
The municipality of Broomfield was incorporated in 1961 in the southeastern corner of Boulder County. In the 1990s, city leaders began to push for the creation of a separate county to avoid the inefficiencies of dealing with four separate court districts, four different county seats, and four separate county sales tax bases. It also had longstanding political differences with Boulder County, which impelled it to separate. Broomfield reasoned that it could provide services more responsively under its own county government, and sought an amendment to the Colorado State Constitution to create a new county. The amendment was passed in 1998, after which a three-year transition period followed. On November 15, 2001, Broomfield County became the 64th, newest, and smallest county of Colorado. It is also the newest county in the United States.