The National Basketball League (NBL) is a men's professional basketball league in Australasia, currently composed of ten teams: nine in Australia and one in New Zealand. It is the premier professional men's basketball league in Australia and New Zealand.
Before the establishment of the NBL, there were two national basketball competitions: the National Titles and the Australian Club Championships.
In August 1979, the inaugural season of the NBL commenced, playing in the winter season (April–September) which it did so until the completion of the 1998 season, the league's twentieth season. The 1998–99 season, which began only months later, was the first to be played during the summer season (October–April). The shift, which is currently used by the league, was an attempt to avoid competing directly against Australia's various winter season football codes. Officially the NBL is Australia's third oldest continuing national sporting competition after the domestic cricket competition (which commenced its first season in 1892) and Australian Football League (which commenced its first season in 1897 as the Victorian Football League before changing its name in 1990).
The NBL experienced its "golden age" in the late 1980s and early 1990s, but its popularity, media attention, attendance and corporate support deteriorated and plateaued in the decade afterward with the growth of the country's four football codes.
A second Melbourne club, the South Dragons, entered the league in the 2006–07 season, but was short lived, soon folding 3 years later after the 2008–09 season in which they were NBL champions. In the 2006–07 season, the NBL became the first Australasian sporting league to field a team from Asia with the Singapore Slingers playing. The Gold Coast Blaze also joined the competition in the 2007–08 season. In 2007, Australian NBA player Andrew Bogut suggested the NBL try to adopt a model similar to the Australian Football League (AFL) whereby there are the same 10 or 15 teams over a 10-year period.
A turbulent period during 2008 and 2009 saw the league lose teams from Sydney, Melbourne, Brisbane and Singapore.
The 2009–10 season earmarked as the season in which the NBL would begin its revamping, much like the old National Soccer League which became the eight team A-League. The NBL returned to free-to-air television in Australia for the first time in three years with One broadcasting 2–3 games a week.
The 2010–11 season saw the return of the Sydney Kings after the club was purchased for A$20,000 on 31 July 2008.
In 2013, the NBL had a de-merger from Basketball Australia.
Crowds improved for the 2013–14 NBL season, recording the highest cumulative crowd attendance figures for the past five years.
After numerous teams folding and a plummeting public profile property developer Larry Kestelman purchased a 51% portion of the league. Since then game attendance, TV viewership, website visitors and app downloads have been consistently on the increase.
In April 2016, the Townsville Crocodiles folded as they had become too financially unsustainable to continue.
Larry Kestelman has stated on the Aussie Hoopla podcast that no NBL club will ever fold again as long as he is in control of the league.
Allowing for clubs to recruit the best Australian players not in the NBA became easier with the marquee rule which saw the return from Europe and the US of players such as Brad Newley, David Andersen and Andrew Bogut. In addition the Special Restricted Player rule, introduced for the 2016–17 season, allows for clubs to recruit players born in countries such as China, Philippines, Taiwan, India, South Korea, Singapore, and Japan who would not count as imports under NBL rules.
From 2016 to 2018, there was a renewed interest in the sport, with it being described as being the National Basketball League's greatest ever period. 2016–17 set a new attendance record for the league, with the figure being matched the following year, as well as the Grand Final series for the 2017–18 season.
In 2018, the S.E. Melbourne Phoenix were announced as the latest club to join the league, and started competing in the 2019–20 season; a season which was widely regarded as a major season for the league. After an active off-season, including the signings of LaMelo Ball and R. J. Hampton, two highly rated NBA 2020 draft picks, the league started by continuing to topple attendance records from the first round. The season's opening night had 10,300 fans in attendance to watch Melbourne United and the S.E. Melbourne Phoenix compete in the first "Throwdown", with a further 20,550 fans attending games across the first round. After signing a broadcasting deal with Facebook Watch, over one million American fans watched Ball's first game in the NBL against the Brisbane Bullets.
Following two condensed seasons due to the COVID-19 pandemic, the 2022–23 NBL season and the 2023 finals series saw a number of all-time attendance records being set for the league.
In the 2023–24 season, one million fans attended NBL games for the first time since 1996.