Waltham is a town in Addison County, Vermont, United States.

[3] Waltham is located in northern Addison County, in the Champlain Valley.

It is bordered by the city of Vergennes to the northwest, the town of Ferrisburgh to the north, New Haven to the east and south, Addison to the southwest, and Panton to the west.

Otter Creek, one of the longest rivers in Vermont, forms the western border.

The racial makeup of the town was 98.75% White, 0.42% African American, 0.63% Asian, 0.21% from other races.