John Job Crew Bradfield was an Australian engineer best known as the chief proponent of the Sydney Harbour Bridge, of which he oversaw both the design and construction. He worked for the New South Wales Department of Public Works from 1891 to 1933. He was the first recipient of an engineering doctorate from the University of Sydney, in 1924. Other notable projects with which he was associated include the Cataract Dam, the Burrinjuck Dam, and Brisbane's Story Bridge. The Harbour Bridge formed only one component of the City Circle, Bradfield's grand scheme for the railways of central Sydney, a modified version of which was completed after his death. He was also the designer of an unbuilt irrigation project known as the Bradfield Scheme, which proposed that remote areas of western Queensland and north-eastern South Australia could be made fertile by the diversion of rivers from North Queensland.

The Sydney Harbour Bridge is a steel through arch bridge in Sydney, New South Wales, Australia, spanning Sydney Harbour from the central business district (CBD) to the North Shore. The view of the bridge, the harbour, and the nearby Sydney Opera House is widely regarded as an iconic image of Sydney, and of Australia itself. Nicknamed "The Coathanger" because of its arch-based design, the bridge carries rail, vehicular, bicycle and pedestrian traffic.