Brooklyn is a suburb and the northern most town on the Pacific Highway in Sydney, New South Wales, Australia. Brooklyn is located on the northern outskirts of Sydney and is located in the local government area of the Hornsby Shire with a population of 737 as of the 2021 census. Brooklyn is surrounded by the Muogamarra Nature Reserve and occupies a strip of waterfront along the southern bank of the Hawkesbury River.

The Hawkesbury River railway bridge is a heritage-listed railway bridge in New South Wales, Australia that carries the Main North railway line across the Hawkesbury River. The bridge crosses between Brooklyn on the northern outskirts of Sydney and Cogra Bay in the Central Coast region. The railway bridge was to be the last link in a railway network that linked the state capitals Adelaide, Melbourne, Sydney and Brisbane and was a major engineering feat at the time. The original railway bridge was built in 1889 and replaced by the current bridge in 1946. The 1946 bridge was added to the New South Wales State Heritage Register on 2 April 1999.