| 2021 AFL premiership season | |
|---|---|
 | |
| Date | 16 March – 25 September 2021 |
| Teams | 18 |
| Premiers | Melbourne 13th premiership |
| Runners-up | Western Bulldogs (2nd runners-up) |
| Minor premiers | Melbourne 10th minor premiership |
| Brownlow Medallist | Ollie Wines (Port Adelaide – 36 votes) |
| Coleman Medallist | Harry McKay (Carlton – 58 goals) |
| Attendance | |
| Matches played | 207 |
| Total attendance | 3,976,228 (19,209 per match) |
| Highest | 78,113 (Round 6, Collingwood vs Essendon) |
The 2021 AFL season was the 125th season of the Australian Football League (AFL), the highest-level senior men's Australian rules football competition in Australia, which was known as the Victorian Football League until 1989. The season featured eighteen clubs, ran from 18 March until 25 September, and comprised a 22-game home-and-away season followed by a finals series featuring the top eight clubs.
The season was played during the second year of the COVID-19 pandemic, and saw disruptions but to a much lesser extent than the 2020 season. Virus outbreaks resulted in restrictions on crowds and the relocation of forty games outside their originally fixtured states, but the season was played without suspension and with only minor disruptions to the scheduled dates of matches.
The premiership was won by the Melbourne Football Club for the 13th time, after it defeated the Western Bulldogs by 74 points in the 2021 AFL Grand Final, which was played at Optus Stadium in Perth.