The 2015–16 season was the 12th in the history of Adelaide United Football Club since its establishment in 2003. The club participated in the A-League for the 11th time, the FFA Cup for the second time and the AFC Champions League for the fifth time.

Ahead of the season, manager Josep Gombau stood down, citing family reasons. He was replaced by the club's technical director, Guillermo Amor, in his first senior managerial role. Adelaide United were knocked out of the FFA Cup in the quarter-finals by rivals Melbourne Victory, their first loss in the competition's history. Two and a half weeks later, Adelaide would begin their season by hosting Victory at Adelaide Oval, a match that ended 0–0. The Reds went winless in their first eight games and sat 13 points from the top of the ladder. From round nine onwards, the club went on a 14-match unbeaten run, which saw them sit atop the ladder by the end of it, following a 4–0 win over Wellington Phoenix. A loss to Melbourne City and a draw with the Western Sydney Wanderers put their title charge in doubt. Adelaide won their remaining three matches and thanks to Melbourne Victory's draw with Brisbane Roar in the final round, Adelaide United were premiers by a solitary point.

Adelaide played Melbourne City in the semi-final. After a scoreless first half, Bruce Djite broke the deadlock in the 48th minute, curling the ball into the top right corner from outside the box. Djite would double their lead from the penalty spot 12 minutes later. Fitzgerald pulled a goal back for Melbourne City, but late goals from Dylan McGowan and Pablo Sánchez saw Adelaide into their third Grand Final, which would also be their first time hosting the match. Second-placed Western Sydney Wanderers travelled to Adelaide Oval for the Grand Final. Bruce Kamau scored in the 21st minute and won a free kick that was converted by Isaías in the 32nd minute. Scott Neville's goal just shy of the hour mark brought the Wanderers back into the game, but Adelaide held on, with Pablo Sánchez eventually scoring Adelaide's third to seal the win. This was Adelaide United's first Australian title, and to this day, their last Grand Final they have played in.

Despite the success, Adelaide lost numerous key players ahead of next season, including Bruce Kamau, Pablo Sánchez, Craig Goodwin, Stefan Mauk and Bruce Djite.

Kits

Coaching staff Position NameHead coach Guillermo AmorAssistant coaches Pau Martí Michael ValkanisGeneral manager Ante KovacevicGoalkeeping coach Peter BlazincicHigh performance manager Greg KingClub doctor James IlicHead trainer Peter DukeHead physiotherapist Peter Chitti

Players Squad

Transfers and contracts Transfers in No.PositionPlayerFromType/feeContract lengthDateRef 3 Western Sydney WanderersFree transfer2 years27 June 2015 14 Free transfer1 year4 July 2015 19 Loan1 year26 July 2015 17 UnattachedFree transfer1 year16 August 2015 6 Melbourne CityPlayer swap2.5 years23 January 2016 18 UnattachedGuest player1 week3 February 2016

Transfers out No.PositionPlayerToType/feeDateRef 3 Newcastle JetsFree transfer30 June 2015 14 UnattachedEnd of contract30 June 2015 19 UnattachedEnd of contract30 June 2015 20 Central Coast MarinersFree transfer8 July 2015 17 $1,300,00020 July 2015 32 UnattachedMutual termination28 December 2015 5 Melbourne CityPlayer swap23 January 2016 18 $400,00027 January 2016 18 UnattachedEnd of contract9 February 2016

Contract extensions No.PositionPlayerContract lengthDateRef 20 2 years11 August 2015 21 3 years29 September 2015 23 1.5 years23 February 2016

Pre-season and friendlies

Competitions Overall record

A-League

League table

Results summary

Results by round

Matches

Finals series

FFA Cup

AFC Champions League

Qualifying play-off

Statistics Appearances and goals

!colspan="14"|Player(s) transferred out but featured this season

See also 2015–16 Adelaide United FC (W-League) season

References