2021 A-League finals series

The 2021 A-League finals series was the 16th annual edition of the A-League finals series, the playoffs tournament staged to determine the champion of the 2020–21 A-League season. The series was played over three weeks culminating in the 2021 A-League Grand Final, where premiers Melbourne City won their first championship 3–1 against reigning champions Sydney FC.

The series dates were extended due to the COVID-19 restrictions in Victoria.

Qualification
Melbourne City and Sydney FC finished in the top two spots to automatically qualify for the semi-finals. Central Coast Mariners qualified for the finals series for the first time since 2014 and Macarthur FC were confirmed their finals qualification in their inaugural season. Brisbane Roar sealed their finals spot after defeating Perth Glory 2–1 to rule them out of the finals series, leaving one spot remaining. Adelaide United became the last to finish in the top six and qualify for the finals series after a 2–2 draw with the Western Sydney Wanderers.

Bracket
The system used for the 2021 A-League finals series is the modified top-six play-offs by the A-Leagues. The top two teams enter the two-legged semi-finals receiving the bye for the elimination-finals in which the teams from third placed to sixth place enter the elimination-finals with "third against sixth" and "fourth against fifth". Losers for the elimination-finals are eliminated, and winners qualify for the semi-finals.

First placed team in the semi-finals plays the lowest ranked elimination-final winning team and second placed team in the semi-finals plays the highest ranked elimination-final winner. Home-state advantage goes to the team with the higher ladder position.



Elimination-finals
Third-placed Central Coast Mariners qualified for the finals series for the first time since 2014 to set up a home elimination-final against inaugural sixth-placed Macarthur FC. No goals were scored in the full 90 minutes, as the match was sent to extra time and ten-man Macarthur scoring two goals by Charles M'Mombwa and Michael Ruhs to win the match 2–0 and send them through to the semi-final against Melbourne City.

Fourth-placed Brisbane Roar; an undefeated side in hosting finals at home went up against fifth-placed Adelaide United who returned to the finals series after missing out in the previous season. Tomi Juric scored two quick-fire goals in the first half and despite a goal back by Alex Parsons for Brisbane, Adelaide United won 2–1 to qualify for the semi-final against Sydney FC.

Semi-finals
Sydney FC and Adelaide United met in the semi-finals at Netstrata Jubilee Stadium. Sydney held the advantage with two goals up at half time through Adam Le Fondre and Bobô. Adelaide in the second half scored one in the second half, but the match resulted in Sydney FC qualifying for the Grand Final for the third consecutive time.

Initially set to be played at AAMI Park, this semi-final between Melbourne City and Macarthur FC was relocated at Netstrata Jubilee Stadium in response to COVID-19 restrictions in Melbourne. Melbourne City successfully booked their spot in the Grand Final, after winning 2–0 against Macarthur thanks to quick-fire goals by Stefan Colakovski and Marco Tilio to qualify for their first home Grand Final.

Grand Final
The 2021 Grand Final was the first rematch of two teams from the previous edition, of Melbourne City and Sydney FC. City won the host of this grand final; this being their first home Grand Final, played at AAMI Park. The capacity was limited to 50% due to COVID-19 restrictions in Melbourne, as all match tickets were sold out for a crowd of almost 15,000. Melbourne City were looking for their first Grand Final success, while Sydney FC were on the verge of three consecutive A-League championships. Sydney opened the scoring through Kosta Barbarouses, until City immediately responded with an equalising goal by Nathaniel Atkinson. City were awarded a penalty which was converted by captain Scott Jamieson towards the end of the first half. Scott Galloway capitalised the match with a third goal to win the match 3–1 for City, winning their first A-League championship.