The Glebe Island Bridge is a heritage-listed disused swing Allan truss road bridge that carried Victoria Road (as Bank Street) across Johnstons Bay, located in the inner city Sydney suburb of Pyrmont, New South Wales, Australia.

The bridge, which connected Rozelle to Pyrmont by road, is one of the last remaining swing bridges of its type in Australia and in the world. It was designed by Percy Allan, and built from 1899 to 1903 by the Bridges Branch of NSW Public Works Department.

Sydney was declared a city in 1842 and was concentrated in the area currently occupied by the modern CBD. In the mid-1800s, it was a mix of commerce, retail, residences, manufacturing works and factories, with the Botanic Gardens and Domain to the east, port activities to the west and north and road outlets at its southern border leading to the inner western suburbs via the Parramatta Road, which was also the beginning of the Great Western Highway. By mid-century, it had become clear that a shorter route out of the city was available, across Johnstons Bay to the Glebe Island and on to Annandale. and was listed on the (now defunct) Register of the National Estate on 19 April 1989.

The first Glebe Island Bridge was a private toll-bridge completed in 1862 and was a timber beam viaduct with a small, one arm, hand-cranked swing-span tucked into the Pyrmont shore. After 30 years, this bridge was in need of extensive repairs and the Colonial Government purchased the structure and the Public Works Department (PWD) began planning a replacement bridge. Work on the new Pyrmont Bridge and the bridge across Black Wattle Swamp shortened the travel distance to the inner west suburbs making it easier for produce to be conveyed to the city. A previously un-used part of Johnstons Bay was promoted as the site for a larger abattoir than the others previously used around the closer areas of high water. The new abattoir, to be opened in January 1860, was provided a punt system to cross the short distance to Pyrmont. Work commenced on the first Glebe Island bridge in 1860; and the first bridge opened for traffic in 1861.

The construction of the second bridge related also to a project commenced in the 1880s for the Five Bridges Route, to facilitate traffic flow from the city to the northern and western suburbs of the expanding city. Bridges were to be built or replaced at Pyrmont Bay, Glebe Island, Iron Cove, Gladesville and Fig Tree (until these bridges were built, the only access to the northern shore of the Harbour was by boat, punt or by road via Parramatta). For this project, the (old) Pyrmont Bridge and the (old) Glebe Island Bridge were purchased from their private owners and new bridges were built at Gladesville (1881), Iron Cove (1882) and Fig Tree (1885).

These completed, attention turned to replacement of the Pyrmont and Glebe Island Bridges. The Sydney Morning Herald reported in September 1890:

"The Departmental Board appointed by the Minister for Public Works nearly a year ago to consider the desirability of constructing new bridges to replace the present Pyrmont and Glebe Island bridges ... has now furnished the Minister with a lengthy report on the subject. The Board has decided in favour of the construction of a new bridge adjoining the present Pyrmont Bridge. The structure recommended is an iron or steel superstructure on cast-iron cylinders, with a roadway 12ft, in width, and two 12ft. footpaths. ...With regard to the Glebe Island Bridge, the Board recommended the construction of a bridge close to the present one, of a character similar to the proposed Pyrmont Bridge, at a cost of £140,000."

An international design competition for a new "Pyrmont Bridge" was called in 1891. The Department of Public Works submitted a non-conforming design based upon a much larger bridge than specified in the design brief.