The Shinnecock Canal Railroad Bridge (also known as the K4 Bridge) is a railroad bridge carrying the Montauk Branch of the Long Island Rail Road over the Shinnecock Canal in Hampton Bays and Shinnecock Hills, Suffolk County, New York, United States.

The Shinnecock Canal Railroad Bridge stands at a height of approximately 22 feet (6.7 meters) above the water and measures 316 feet (96 meters) in length.

"[4] Prior to the current span's construction, these locomotives were unable to cross the bridge due to their weight.

[1][2][4][5] Its construction would enable trains using the Montauk Branch – which predates the canal – to travel over the new waterway.

[1][3] It was replaced by a new, near-identical span adjacent to it in 1931; this third bridge, which remains in use today, was placed into service on June 21 of that year.