Customs House, Sydney is a heritage-listed museum space, visitor attraction, commercial building and performance space located in the Circular Quay area at 45 Alfred Street, in the Sydney central business district, in the City of Sydney local government area of New South Wales, Australia. The building served as a customs house prior to Federation and then as the head office of New South Wales operations of the Government of Australia agency Department of Trade and Customs (and its successors) until 1988. The customs function relocated to a new site in 1990. The initial designs were by Mortimer Lewis and it was built during 1845 by under the administration of Governor Sir George Gipps. It is also known as Customs House (former) and Site of former Customs House. The site was added to the Commonwealth Heritage List on 22 June 2004; and to the New South Wales State Heritage Register on 2 April 1999.

Circular Quay is a harbour, former working port and now international passenger shipping terminal, public piazza and tourism precinct, heritage area, and transport node located in Sydney, New South Wales, Australia on the northern edge of the Sydney central business district on Sydney Cove, between Bennelong Point and The Rocks. It is part of the local government area of the City of Sydney.