The Macquarie Lighthouse, also known as South Head Upper Light, was the first, and is the longest serving, lighthouse site in Australia. It is located on Dunbar Head, on the Old South Head Road, Vaucluse in the Municipality of Woollahra local government area of New South Wales, Australia. The lighthouse is situated approximately 2 kilometres south of South Head near the entrance to Sydney Harbour. There has been a navigational aid in this vicinity since 1791 and a lighthouse near the present site since 1818. The current heritage-listed lighthouse was completed in 1883. The lighthouse and associated buildings were designed by James Barnet and built from 1881 to 1883.
The lighthouse is fully operational and is under the control of the Australian Maritime Safety Authority. The grounds are managed by the Sydney Harbour Federation Trust.
The lighthouse is featured on the coat of arms of Macquarie University. In 2008, the University introduced an official logo, described as an 'abstract, timeless image' of water lilies, as its public visual identity; use of the arms was subsequently restricted to official documents such as graduation testamurs and legal documentation.