Weld County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 328,981. The county seat is Greeley.

Greeley is the home rule municipality city that is the county seat and the most populous municipality of Weld County, Colorado, United States. The city population was 108,795 at the 2020 United States Census, an increase of 17.12% since the 2010 United States Census. Greeley is the tenth most populous city in Colorado. Greeley is the principal city of the Greeley, CO Metropolitan Statistical Area and is a major city of the Front Range Urban Corridor. Greeley is located in northern Colorado and is situated 49 miles (79 km) north-northeast of the Colorado State Capitol in Denver.