In October 2018, following the demise of the South East Australian Basketball League, Basketball Victoria announced a new senior elite league to take the reins as Australia's pre-eminent semi-professional basketball league. All Victorian-based SEABL teams joined the new league, while Eltham Wildcats, Knox Raiders, Ringwood Hawks and Waverley Falcons also joined the league from the Big V State Championship Division. The North-West Tasmania Thunder men and Launceston Tornadoes women also kept their place, as did Basketball Australia's Centre of Excellence teams. In February 2019, the league was named NBL1.
Expansion
After a successful first season, the league announced in October 2019 that it would be expanding into Queensland for the 2020 season. In January 2020, NBL1 expanded with the establishment of North and South conferences for the 2020 season. After a landmark agreement with Basketball Queensland, NBL1 North replaced the Queensland Basketball League. As a result, the 2019 NBL1 teams formed the new south conference. The following month, NBL1 expanded into South Australia after an identical agreement with Basketball South Australia for NBL1 Central to replace the Premier League. However, the threat of the COVID-19 pandemic forced the 2020 season to be cancelled.
Conferences
South Conference
Founded in 2019, the South Conference was the only conference in NBL1 during its inaugural season and predominately consisted of teams from the defunct South East Australian Basketball League. The South Conference currently has 18 teams spread across Victoria, Tasmania, New South Wales and South Australia.
North Conference
In 2020, the North Conference joined the league, becoming the second conference introduced following NBL1's merger with the former Queensland Basketball League. The North Conference currently consists of 13 teams, all of which are based in Queensland.
Central Conference
In 2020, the Central Conference joined the league, becoming the third conference introduced following NBL1's merger with the former South Australian Premier League. The Central Conference currently consists of 10 teams, all of which are based in South Australia.
Current clubs
* Teams that transferred from the South East Australian Basketball League. ** Teams that transferred from the Queensland Basketball League. *** Teams that transferred from the Premier League. **** Teams that transferred from the Big V.
