Dee Why is a coastal suburb of northern Sydney, in the state of New South Wales, Australia, 18 kilometres north-east of the Sydney central business district. It is the administrative centre of the local government area of Northern Beaches Council and, along with Brookvale, is considered to be the main centre of the Northern Beaches region.

Public transport in Dee Why primarily runs along Pittwater Road in the form of buses, with services southwards to the city, Manly and North Sydney, and northwards to Collaroy, Cromer, Narrabeen, and the Pittwater area. The main bus stop for these services is located at the intersection with Howard Avenue. There are also semi-regular services to Chatswood via Warringah Road to the west. Dee Why also has a B-Line stop to the City or Mona Vale in 10 minutes time Two express services to the city also run from near Dee Why Beach in the early morning and back from the city in the afternoon to serve commuters on weekdays.