Eldorado Springs is an unincorporated community, a census-designated place (CDP) and a post office located in and governed by Boulder County, Colorado, United States. The CDP is a part of the Boulder, CO Metropolitan Statistical Area. The Eldorado Springs post office has the ZIP code 80025. At the 2020 United States census, the population of the Eldorado Springs CDP was 559.

Eldorado Mountain is a mountain summit on the eastern flank of the Front Range of the Rocky Mountains of North America. The 8,344-foot (2,543 m) peak is located 8.1 miles (13.1 km) south by west of downtown Boulder, Colorado, United States. The mountain is largely in Boulder County but it straddles the border and its southern flanks are located in Jefferson County. Its name was probably borrowed from the nearby community of Eldorado Springs.