Hidden Lake is an unincorporated community and a census-designated place (CDP) located in and governed by Boulder County, Colorado, United States.

The population of the Hidden Lake CDP was 24 at the United States Census 2020.

[3] The Ward post office (Zip Code 80481) serves the area.

[4] Hidden Lake is located in western Boulder County in the Front Range of the Colorado Rocky Mountains.

State Highway 72, the Peak to Peak Highway, forms the western edge of the community, leading south 4 miles (6 km) to Ward and 15 miles (24 km) to Nederland, and north 27 miles (43 km) to Estes Park.