Brisbane Water is a wave-dominated barrier estuary located in the Central Coast region of New South Wales, Australia. Brisbane Water has its origin at the confluence of the Narara and Coorumbine Creeks, to the south–east of Gosford and travels for approximately 18 kilometres (11 mi) in a southerly direction to its mouth at Broken Bay, about 7 kilometres (4.3 mi) from the Tasman Sea, at Barrenjoey Head. A number of towns and suburbs surround the shores of Brisbane Water, including Blackwall, Booker Bay, Davistown, Empire Bay, Erina, Ettalong Beach, Gosford, Green Point, Hardys Bay, Kilcare, Kincumber, Koolewong, Phegans Bay, Point Frederick, Point Clare, Saratoga, Tascott, Wagstaffe, and Woy Woy. Contained within Brisbane Water is St Huberts Island, Rileys Island, Dunmar Island and Pelican Island; and adjoining the estuary is Brisbane Water National Park to the west and Bouddi National Park to the east. Forming part of the same tidal estuary system is a separate but connected basin, the Kincumber Broadwater, lying to the east of Davistown.

The Central Coast is a peri-urban region lying on the Pacific Ocean in northern-eastern New South Wales, Australia. The region is situated north of Sydney, which is filled with subtropical national parks, forests and also encompasses the major coastal waterways of Brisbane Water, Tuggerah Lakes and southern Lake Macquarie. The region's hinterland, which has fertile valleys, rural farmland and wineries, and also includes the Watagan Mountains. The Central Coast is known for its regional coastal towns like Terrigal, The Entrance, Ettalong Beach, Budgewoi and Bateau Bay with resorts and holiday parks, which feature many expansive beaches and lagoons with surfing and coastal tracks, as well as scenic views. Gosford is the main commercial hub and gateway.