Long Reef is a prominent headland on the Northern Beaches of Sydney, Australia. Connected to the mainland by a tombolo, the reef has an extensive wave-cut platform. Long Reef is a popular recreational destination and is one of the more interesting geological areas in Sydney.

The Northern Beaches is a region within Northern Sydney, in the state of New South Wales, Australia, near the Pacific coast. This area extends south to the entrance of Port Jackson, west to Middle Harbour and north to the entrance of Broken Bay. The area was formerly inhabited by the Garigal or Caregal people in a region known as Guringai country.