Dubuque County, Iowa

Dubuque County, Iowa
Location within the U.S. state of Iowa
Coordinates: 42°27′49″N 90°52′44″W / 42.463481°N 90.878771°W / 42.463481; -90.878771
Country United States
State Iowa
FoundedOctober 1, 1834
Named afterJulien Dubuque
SeatDubuque
Largest cityDubuque
Area
 • Total
616.461 sq mi (1,596.63 km2)
 • Land608.299 sq mi (1,575.49 km2)
 • Water8.162 sq mi (21.14 km2)  1.32%
Population
 (2020)
 • Total
99,266
 • Estimate 
(2024)
99,242
 • Density163.19/sq mi (63.007/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Area code563
Congressional district2nd
Websitedubuquecountyiowa.gov
  • Iowa county number 31

Dubuque County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 99,266, and was estimated to be 99,242 in 2024, making it the ninth-most populous county in Iowa. The county seat is Dubuque. The county is named for Julien Dubuque, the first European settler of Iowa. Dubuque County comprises the Dubuque, IA Metropolitan statistical area.