Westport hamlet is located in the center of the town of Westport, at the outflow of Hoisington Brook into North West Bay of Lake Champlain.

The CDP extends north along the shore of the lake as far as Cove Lane and south to Maple Way.

The western edge of the CDP is formed by the Delaware and Hudson Railway line and by Hammond Brook.

New York State Routes 9N and 22 intersect in the center of the hamlet.

According to the United States Census Bureau, the Westport CDP has a total area of 2.36 square miles (6.11 km2), all land.