El Dorado County, officially the County of El Dorado, is a county located in the U.S. state of California. As of the 2010 census, the population was 181,058.[3] The county seat is Placerville.

El Dorado County is included in the Sacramento-Roseville-Arden-Arcade, CA Metropolitan Statistical Area. It is located in the historic Gold Country in the Sierra Nevada.

The population of El Dorado County has grown as Greater Sacramento has expanded into the region. In the unique Lake Tahoe area of the county, environmental awareness and environmental protection initiatives have grown along with the population since the 1960 Winter Olympics, hosted at Squaw Valley Ski Resort in neighboring Placer County.