Idledale is an unincorporated town, a post office, and a census-designated place (CDP) located in and governed by Jefferson County, Colorado, United States. The CDP is a part of the Denver–Aurora–Lakewood, CO Metropolitan Statistical Area. The Idledale post office has the ZIP code 80453. At the United States Census 2020, the population of the Idledale CDP was 244.

Jefferson County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 582,910, making it the fourth-most populous county in Colorado. The county seat is Golden, and the most populous city's Lakewood.