The Watertown Bridge is a five-lane traffic bridge over the Charles River, carrying Rt. 16 and Galen Street. It connects Watertown Square on the north side and Watertown Yard on the south side of Watertown, Massachusetts. Pedestrian walkways line each side.

Beginning as a ford, this river crossing has been spanned by bridges since 1641. The current span dates from 1907. Previous bridges date from 1647, 1667, and 1719.

The 1994 film The River Wild opens with Meryl Streep rowing downstream under the Watertown Bridge.