The Stewart Avenue Bridge is a historic structure located in Mason City, in the north-central part of the U.S. state of Iowa.

The span carries North Carolina Avenue over the Winnebago River for 116 feet (35 m).

The Iowa State Highway Commission had the plans completed by November 1913, although the city did not petition the county to have it built until February 1914.

N.M. Stark and Company of Des Moines had the low bid at $12,775, which included the removal of the old bridge.

This article about a property in Cerro Gordo County, Iowa on the National Register of Historic Places is a stub.