The South Street Bridge is a historic Pratt truss bridge, carrying Vermont Route 31 across the Poultney River just south of the village center of Poultney, Vermont.

The bridge is oriented north-south, and the river flows roughly westward, eventually forming the state line with neighboring New York before emptying into Lake Champlain.

The bridge is a typical single-span Pratt through truss structure, with a span of 126 feet (38 m), and rests on abutments of poured concrete with large boulders mixed in.

There is a sidewalk cantilevered outside the downstream truss, and the roadway width is 21 feet (6.4 m) (two lanes).

Its trusses were fabricated by the Palmer Steel Company of Holyoke, Massachusetts.