| 1912 NSWRFL season | |
| League: | New South Wales Rugby Football League |
| Duration: | 4 May to 24 August |
| No Of Teams: | 8 |
| Matches: | 56 |
| Points: | 1262 |
| Season Champs: | Eastern Suburbs[1] |
| Season Champs Count: | 2nd |
| Season Champ Name: | Premiers |
| League Leaders: | Eastern Suburbs |
| League Leaders Count: | 1st |
| League Leaders Name: | Minor Premiers |
| Second Place: | Glebe |
| Top Scorer: | Dally Messenger (80) |
| Top Try Scorer: | Roy Algie (12) |
| Season2: | Second Grade |
| No Of Teams2: | 17 |
| Season Champs2: | Glebe |
| Season Champ Name2: | Premiers |
| Second Place2: | Redfern |
| Season3: | Third Grade |
| No Of Teams3: | 20 (1 disqualified) |
| Season Champs3: | South Sydney |
| Season Champ Name3: | Premiers |
| Second Place3: | South Sydney Federals |
| Prevseason Link: | 1911 NSWRFL season |
| Prevseason Year: | 1911 |
| Nextseason Link: | 1913 NSWRFL season |
| Nextseason Year: | 1913 |
The 1912 New South Wales Rugby Football League premiership was the fifth season of Sydney’s rugby league club competition, Australia’s first. Eight teams from across the city contested during the season for the premiership and the Royal Agricultural Society Challenge Shield.
From 1912 to 1925, the team finishing on top of the ladder after the home-and-away rounds was automatically deemed premiers unless two clubs were on equal points at this point in which case a final was held. This move by the New South Wales Rugby League may well have been in response to Eastern Suburbs’ victory in the season before, where they overcame minor premiers Glebe in two successive finals to claim the premiership.
With four rounds remaining in the 1912 season, Eastern Suburbs and Glebe were clearly ahead of the rest of the teams and it looked unlikely that they would be caught. The two clubs were matched up against each other in Round 11 at the Sydney Sports Ground in what would ultimately decide the fate of the premiership, with Glebe just two points behind Eastern Suburbs on the ladder. In front of 25,000 people, the two clubs played out a closely fought match in muddy conditions. Dally Messenger was able to break a 4–4 deadlock late in the match by kicking a field goal after a scrum win close to the sideline and win the game 6–4 for Eastern Suburbs.
With a four-point premiership lead and only three rounds to play, Eastern Suburbs, who had only lost one game before in the season to eventual third-placed Newtown, looked uncatchable. That turned out to be the case, with Eastern Suburbs winning their remaining three games to take away the premiership.
Also this season Pratten Park became the Western Suburbs club's homeground.
The teams remained unchanged from the previous season.
| width=20 abbr="Position×" | width=175 | Team | width=20 abbr="Played" | Pld | width=20 abbr="Won" | W | width=20 abbr="Drawn" | D | width=20 abbr="Lost" | L | width=20 abbr="Points for" | PF | width=20 abbr="Points against" | PA | width=20 abbr="Points difference" | PD | width=20 abbr="Points" | Pts | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Eastern Suburbs | 14 | 13 | 0 | 1 | 230 | 86 | +144 | 26 | ||||||||||
| 2 | Glebe | 14 | 11 | 0 | 3 | 199 | 83 | +116 | 22 | ||||||||||
| 3 | Newtown | 14 | 9 | 0 | 5 | 178 | 132 | +46 | 18 | ||||||||||
| 4 | South Sydney | 14 | 8 | 0 | 6 | 207 | 137 | +70 | 16 | ||||||||||
| 5 | Balmain | 14 | 6 | 0 | 8 | 138 | 168 | -30 | 12 | ||||||||||
| 6 | North Sydney | 14 | 6 | 0 | 8 | 124 | 197 | -73 | 12 | ||||||||||
| 7 | Annandale | 14 | 2 | 0 | 12 | 86 | 134 | -48 | 4 | ||||||||||
| 8 | Western Suburbs | 14 | 1 | 0 | 13 | 100 | 325 | -225 | 2 | ||||||||||
Eastern Suburbs won the premiership when they beat Norths at North Sydney Oval 15–10 on 17 August. The premiership squad was:[2]