Dillon is a home rule municipality in Summit County, Colorado, United States. The population was 802 at the 2000 census. Dillon was built as a stage stop and trading post on the northeast side of the Snake River in the Blue River Valley. The town was named for Tom Dillon, a prospector. The town was incorporated in 1883.
According to the United States Census Bureau, the town has a total area of 2.4 square miles (6.2 km sq), of which, 1.5 square miles (3.9 km sq) of it is land and 0.9 square miles (2.3 km sq) of it (35.71%) is water. Dillon Dam and its reservoir (Lake Dillon) are nearby. The continental Divide is approximately 10 miles (16 km) east.