Underhill Flats is an unincorporated village and census-designated place (CDP) in the towns of Underhill and Jericho, Chittenden County, Vermont, United States.

The CDP is in northeastern Chittenden County, in the western part of the town of Underhill and the northern part of the town of Jericho.

It sits in the valley of The Creek where it flows into the Browns River, which forms the southern border of the CDP.

Vermont Route 15 passes through Underhill Flats, leading north 11 miles (18 km) to Cambridge and southwest 3 miles (5 km) to Jericho.

Underhill Center is 2.5 miles (4.0 km) to the southeast via River Road, and Burlington, the state's largest city, is 17 miles (27 km) to the west-southwest.