Larkspur is a home rule municipality in Douglas County, Colorado, United States. The town population was 183 at the 2010 census, down from 234 at the 2000 census. Each year, on weekends in June and July, the Colorado Renaissance Festival is held in the hills just west of the town. The town is served by Larkspur Elementary School, a K-6 school in the Douglas County school district.A post office called Larkspur has been in operation since 1871. The community was named for the abundance of larkspur near the original town site.