The Queensboro Bridge, also known as the 59th Street Bridge, because its Manhattan end is located between 59th and 60th Streets and officially titled the Ed Koch Queensboro Bridge, is a cantilever bridge over the East River in New York City that was completed in 1909. It connects the neighbourhood of Long Island City in the borough of Queens with Manhattan, passing over Roosevelt Island. It carries New York State Route 25 and is the westernmost of the four East River spans that carry a route number: NY 25 terminates at the west (Manhattan) side of the bridge, which once carried NY 24 and NY 25A as well. The bridge is flanked on its northern side by the freestanding Roosevelt Island Tramway. In December 2010, the bridge was renamed in honour of former New York City mayor Ed Koch.

Serious proposals for a bridge linking Manhattan to Long Island City were first made as early as 1838 and attempts to finance such a bridge were made by a private company beginning in 1867. Its efforts never came to fruition and the company went bankrupt in the 1890s. Successful plans finally came about in 1903 under the city's new Department of Bridges, led by Gustav Lindenthal, in collaboration with Leffert L. Buck and Henry Hornbostel, designers of the Williamsburg Bridge. Construction soon began, but it would take until 1909 for the bridge to be completed due to delays from the collapse of an incomplete span during a windstorm and from labour unrest including an attempt to dynamite one span. The bridge opened to the public on March 30, 1909, having cost about $18 million and 50 lives. A ceremonial grand opening was held on June 12, 1909. It was then known as the Blackwell's Island Bridge, from an earlier name for Roosevelt Island. Between 1930 and 1955, there was a vehicular elevator to transport cars and passengers to and from Welfare Island, now known as Roosevelt Island. This was demolished in 1970.

The bridge has two levels. Originally the top level contained two pedestrian walks and two elevated railway tracks (which connected a spur of the IRT Second Avenue Elevated Line to the Queensboro Plaza elevated station) and the lower deck four motor traffic lanes, and what is now the "outer roadway" and pedestrian walk were two trolley lanes. A trolley connected passengers from Queens and Manhattan to a stop in the middle of the bridge, where passengers could take an elevator or the stairs down to Roosevelt Island. The trolley operated from the bridge's opening until April 7, 1957. The railway was removed in the late 1930s and early 1940s as well as the 2nd Avenue Elevated Line. The trolley lanes and mid-bridge station, as well as the stairs, were removed in the 1950s, and for the next few decades the bridge carried 11 lanes of automobile traffic. No tolls are charged for motor vehicles to use the bridge.

Films that feature the Queensboro Bridge include: