The 1908 NSWRFL season was the inaugural season of the New South Wales Rugby Football League's premiership, Australia's first rugby league football club competition, in which nine clubs (eight from Sydney and one from Newcastle) competed from April till August 1908. The season culminated in the first premiership final, for the Royal Agricultural Society Challenge Shield, which was contested by Eastern Suburbs and South Sydney. In 1908 the NSWRFL also assembled a New South Wales representative team for the first ever interstate series against Queensland, and towards the end of the season, the NSWRFL's leading players were absent, having been selected to go on the first Kangaroo tour of Great Britain.

Early in the 20th century in Sydney, the game of rugby football was contested in competitions that were affiliated with the Rugby Football Union based in England. In 1895 the breakaway Northern Rugby Football Union was formed and its own version of rugby football started to evolve. The reasons for this split were ultimately based on the fact that clubs had wanted to compensate their players for time away from work due to injuries and travelling. After the Rugby Football Union denied the clubs' requests for compensation, many northern English clubs broke away and formed a new league, which implemented gradual rule changes to the football it played in an attempt to make a more attractive game for crowds. When crowd numbers started to rise, clubs were able to afford to pay players benefits as a direct result of increased gate takings.

In 1906 in Sydney, crowd numbers for football matches began to increase significantly following the emergence of an especially talented player, Dally Messenger, whose skill was considered a pleasure to watch. It was around this time that the discontent of players with their clubs for failing to shift away from the amateur culture of the Rugby Football Union was starting to show. Even though bigger crowds had brought increased revenue to the game, footballers did not see any of the increased revenue going back to them. On 8 August 1907 a group of leading players and supporters met at Bateman's Hotel, George Street, Sydney and resolved to form the New South Wales Rugby Football League (NSWRFL). In the latter half of 1907, and unknown to the general public, Dally Messenger secretly agreed to sign on to play in a breakaway professional competition that would start the following year, run by the NSWRFL. It would turn out to be Messenger's popularity that would ensure the success of the new competition.

Early in 1908, a number of Rugby Football Union clubs held meetings across Sydney and Newcastle to decide whether or not breakaway clubs should be formed in preparation for the new Rugby Football League's premiership that was to start in the following months. The popularity amongst players in support of the new competition was overwhelming, with only some players deciding to continue playing in the traditional amateur Rugby Football Union competition. The Rugby Football League clubs that were formed were essentially breakaway clubs, and in most instances, teams continued the use of their team colours into the new competition. A key aspect of the new code was that players would be paid for playing the game. Adopting the playing rules of the rebel Northern Union of England, the new competition began on Easter Monday, 20 April 1908.

The 1907–08 All Golds arrived back in Australia on 9 April. They spread themselves around the eight clubs that were preparing for the season. They helped advise them on the rules of rugby league. The team watched the first round of the competition before heading to Newcastle and playing the first game of rugby league in that city. They then played matches against New South Wales and Australia before heading north to Queensland. The final test was held on 6 June and Australia defeated New Zealand 14–9 for their first test win.

A New Zealand Māori side had arrived in Sydney in the first week of June and watched the All Golds' final test. They played four matches in New South Wales before also heading north to Queensland. On their return they played three more matches, including one against Australia, before financial and legal disputes ended the tour.

Eight teams contested the first round of the season; seven teams from Sydney and one team from Newcastle. Another Sydney team, Cumberland, joined the competition in the second round, making it nine teams in total, however the club exited the League at the end of the season.

All four games of the premiership's opening round were played on 20 April 1908. Two games were held at Wentworth Park and the other two at Birchgrove Oval. In total, 3000 people attended at each venue for the back-to-back matches, with Glebe, Balmain, South Sydney and Eastern Suburbs winning their respective matches over Newcastle, Western Suburbs, North Sydney and Newtown. In all, ten regular-season rounds were played, to be followed by two semi-finals and then a final.