Deer Lodge County is a county in the U.S. state of Montana. As of the 2020 census, the population was 9,421. It forms a consolidated city-county government with its county seat of Anaconda. The county was established in 1865.

Anaconda, county seat of Deer Lodge County, which has a consolidated city-county government, is located in southwestern Montana, United States. Located at the foot of the Anaconda Range, the Continental Divide passes within 8 mi (13 km) south of the community. As of the 2020 census the population of the consolidated city-county was 9,421, and the US Census Bureaus's 2015-2019 American Community Survey showed a median household income of $41,820. Anaconda had earlier peaks of population in 1930 and 1980, based on the mining industry. As a consolidated city-county area, it ranks as the ninth most populous city in Montana, but as only a city is far smaller. Central Anaconda is 5,335 ft (1,626 m) above sea level, and is surrounded by the communities of Opportunity and West Valley.