Asbury is a city in Dubuque County, Iowa, United States, and adjacent to the westside of the city of Dubuque. It is part of the Dubuque, Iowa Metropolitan Statistical Area. The population was 5,943 at the 2020 census. Asbury is the second-largest city in Dubuque County, surpassing Dyersville to become the second-largest in the 2010 U.S. Census count. The city is largely a bedroom community, made up of subdivisions whose residents work in Dubuque or Peosta.