The Calhoun Street Extension is a series of roads in Trenton, New Jersey, and nearby Lawrence Township.

It runs from the Calhoun Street Bridge over the Delaware River to Brunswick Circle, and is composed of the following named streets: The Extension was built as a joint undertaking by the New Jersey State Highway Commission, the city of Trenton and Mercer County; it opened in January 1932.

New roads built were the Brunswick Circle Extension and the northeast part of Calhoun Street; the rest of Calhoun Street and Princeton Avenue existed before the road was built.

The road was intended as a bypass of Downtown Trenton for cars and light trucks; the Calhoun Street Bridge had and still has a low weight limit.

On the Pennsylvania side of the Delaware River, the road from the bridge rejoined the Lincoln Highway to Philadelphia at Fallsington.