Buses account for close to six per cent of trips each day in the city of Sydney, New South Wales, Australia, forming a key part of the city's public transport system. The network initially evolved from a privately operated system of feeder services to railway stations in the outer suburbs, and a publicly operated network of bus services introduced to replace trams in the inner suburbs. The bus network has undergone major reforms since the 2000s–2010s, with the New South Wales Government taking responsibility for route and fare-setting, opening contracts for most routes up to competitive tendering, and introducing more cross-suburban services.

Transport for NSW (TfNSW) is a New South Wales government transport and road agency established on 1 November 2011. The agency is a different entity to the New South Wales Department of Transport, a department of the New South Wales Government and the ultimate parent entity of Transport for NSW.