The Mill River is a 17.8-mile-long (28.6 km)[1] tributary of Otter Creek in Rutland County, Vermont, in the United States.

The Mill River rises in the southern part of the town of Mount Holly, west of the Okemo Mountain ski area in the Green Mountains.

It flows northwest, paralleled by Vermont Route 155, to the village of East Wallingford, where it continues north and northwest paralleled by Vermont Route 103 and the Green Mountain Railroad.

It turns west and then southwest at the village of East Clarendon, passes under U.S. Route 7, and reaches Otter Creek 1 mile (2 km) southwest of the village of Clarendon.

This article related to a river in Vermont is a stub.