Dyersville is a city in eastern Delaware County and western Dubuque County in the U.S. state of Iowa. It is part of the Dubuque, Iowa, Metr…Dyersville is a city in eastern Delaware County and western Dubuque County in the U.S. state of Iowa. It is part of the Dubuque, Iowa, Metropolitan Statistical Area. The population was 4,477 at the time of the 2020 census, up from 4,035 in 2000.