2019–20 Big Bash League season
| Dates | 17 December 2019 – 8 February 2020 |
|---|---|
| Administrator | Cricket Australia |
| Cricket format | Twenty20 |
| Tournament format(s) | Double round robin and Playoffs |
| Champions | Sydney Sixers (2nd title) |
| Participants | 8 |
| Matches | 61 |
| Attendance | 1,119,541 (18,353 per match) |
| Player of the series | Marcus Stoinis (Melbourne Stars) |
| Most runs | Marcus Stoinis (Melbourne Stars) (705) |
| Most wickets | Daniel Sams (Sydney Thunder) (30) |
| Official website | bigbash.com.au |
The 2019–20 Big Bash League season or BBL|09 was the ninth season of the Big Bash League, the professional men's Twenty20 domestic cricket competition in Australia. The tournament started on 17 December 2019 and concluded on 8 February 2020.
The length of the season was shortened from the previous season, although the number of matches was increased from 59 to 61. The post-season stage of the tournament was revamped into a play-off system, with the top two teams in the league getting a second chance to advance to the final even if they lost the first match in the play-offs.
Melbourne Renegades were the defending champions, but finished last in the group stage. In the final, Sydney Sixers beat Melbourne Stars by 19 runs.