The 2018–19 Adelaide United FC season was the club's 15th season since its establishment in 2003. The club participated in the A-League for the 14th time and the FFA Cup for the 5th time.
Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply. Players may hold more than one non-FIFA nationality.
Source: A-Leagues Rules for classification: 1) points; 2) goal difference; 3) number of goals scored. (C) Champions Notes:
^ abcThe top two teams enter the Finals series at the semi-finals, while the teams ranked third to sixth enter the Finals series at the elimination-finals.
^Wellington Phoenix cannot qualify for the AFC Champions League as they are not recognised as an AFC club.