The South Market Street Bridge, officially the Senator John E. Reilly, Sr. Bridge, is a bascule bridge that spans the Christina River in Wilmington, Delaware.

Its construction was administered by the then State Highway Department (predecessor of the Delaware Department of Transportation), and was built to replace the swing bridge that was built in 1883 to replace the wooden turn bridge built in 1808.

In 1982, the bridge was named after Wilmington state Senator John Edward Reilly Sr., a gravel-voiced cigar smoker known for his warmth and wit, who died of cancer on February 26, 1963.

The bridge underwent a major rehabilitation in 2004–2006 to replace and upgrade the existing machinery and improve lighting, pedestrian walkways, and the operator towers.

This article about a bridge in Delaware is a stub.