Hawkesbury River Railway Bridge, Railway bridge crossing the Hawkesbury River in New South Wales, Australia

The Hawkesbury River Railway Bridge is a steel truss bridge with a curved, arched profile that crosses the Hawkesbury River between Brooklyn and Cogra Bay. It has eight spans of three different lengths, with dark crisscrossing latticework resting on rectangular concrete piers sunk to depths of up to 56 metres. The bridge opened in 1946, 60 metres upstream of the original 1889 structure.

The Union Bridge Company of New York built the first bridge, which opened on 1 May 1889 with seven 127-metre spans and five piers sunk 46 to 49 metres below high water. A 1938 pier crack and wartime traffic led to a replacement, begun in 1940 and opened on 1 July 1946, set 60 metres upstream with eight spans and piers up to 56 metres deep.

The bridge completed the rail link between Adelaide, Melbourne, Sydney and Brisbane, and its opening on 1 May 1889 drew dignitaries including Henry Deane, assistant engineer-in-chief of the New South Wales Government Railways. Before it opened, northbound passengers left the train at Long Island and crossed the Hawkesbury on the paddle steamer General Gordon, a three-hour trip to Gosford via Broken Bay and Brisbane Water.

The bridge carries the Main North railway line and enables train service connecting several Australian states. Visitors can view and photograph the structure from various vantage points along the river.

The 1889 bridge's seven 127-metre spans were assembled on Dangar Island and floated about 1,500 metres to the site on barges; the present 1946 bridge, 60 metres upstream, was built in place. Five of the old piers reached 46 to 49 metres below high water, among the deepest of their day.