Dee Why postcode 2099 is both a suburb of Sydney's Northern Beaches and a beach within the suburb. Neighbouring suburbs include Cromer, Collaroy, Narraweena and Curl Curl.
The name of neighbouring Long Reef is obvious but, the Dee Why name is shrouded in mystery with some suggesting it relates back to a DY-like rock inscription supposedly of early Spanish origin. [1]
The beach runs for 1.8 km. The dense residential development impinges on the back of the beach, with the foreshore given over to a large car park, Dee Why Surf Life Saving Club, an extensive park and picnic area running out to the point where a rock pool is located.
On The Strand, the street that runs along the beachfront, there are many cafés, restaurants and bars.
There is also Dee Why Lagoon. The high conservation value of the lagoon and its surrounding area was recognised in 1973 when it was proclaimed a Wildlife Refuge. The Dee Why Lagoon Wildlife Refuge covers an area of 69 hectares. It is a major scenic feature of the Northern beaches, being situated off the main road, Pittwater Road.
Dee Why is within the Warringah local government area, however in recent years there have been calls for the neighbouring councils Manly and Pittwater to merge with Warringah council in order to form one single government council for the Northern Beaches area.
Dee Why was also the name of a ferry that, for forty years between 1928 and 1968 serviced the Manly area. See Dee Why ferry.