Auraria was a small mining settlement in the Kansas Territory in the United States. It was located in present-day Colorado south of the confluence of Cherry Creek and the South Platte River in present-day Denver.

The town was founded by William Green Russell and party of fellow settlers from Georgia on November 1, 1858, three weeks before William Larimer plated the future "Denver City" across Cherry Creek. The town was named for the gold mining settlement of Auraria, Georgia. Auraria declined at Denver's expense when Russell and many of his party returned to Georgia at the outbreak of the American Civil War in order to fight for the Confederacy.

In April 1859 Auraria was the site of a small convention of settlers with the intention of creating a local government out of Arapaho County, the western portion of the Kansas Territory. The settlers chose the name "Jefferson" in honor of Thomas Jefferson. On August 1, 37 district representatives met to draft a constitution for the provisional "State of Jefferson", which was subsequently rejected in a popular referendum on September 24. The original authors determined to hold another convention on October 3, and drafted a provisional constitution for the Territory of Jefferson. The territory was never recognized by the U.S. government, and it ceased to exist even unofficially when the Colorado Territory was organized by the Act of Congress in 1861. By that time, Auraria had been eclipsed by Denver, which had been designed as the county seat of Arapaho County and which was subsequently chosen as the territorial capital.

The name "Auraria" survives in Denver as the neighborhood along the south bank of Cherry Creek near the South Platte. Auraria is distinct from the city of Aurora, Colorado, which is east of Denver.