South East Queensland (SEQ) is a bio-geographical, political, and administrative region of the state of Queensland in Australia, which contains more than 3.6 million people out of the state's population of 5.1 million. The area covered by South East Queensland varies, depending on the definition of the region, though it tends to include Queensland's three largest cities: the capital city Brisbane; the Gold Coast; and the Sunshine Coast. Its most common use is for political purposes, and covers 22,420 square kilometres (8,660 sq mi) and incorporates 11 local government areas, extending 240 kilometres (150 mi) from Noosa in the north to the Gold Coast and New South Wales border in the south (some sources include Tweed Heads (NSW) which is contiguous as an urban area with Brisbane/Gold Coast), and 140 kilometres (87 mi) west to Toowoomba (which is simultaneously considered part of the Darling Downs region).
South East Queensland was the first part of Queensland to be settled and explored by Europeans. Settlements initially arose in the Brisbane and Ipswich areas with activity by European immigrants spreading in all directions from there. Various industries such as timber cutting and agriculture quickly developed at locations around the region from the 1840s onwards. Transport links have been shaped by the range of terrains found in South East Queensland.
The economy of South East Queensland supports and relies on a wide diversity of agricultural manufacturing industries, commerce and tourism. The region has an integrated public transport system, TransLink.