[1] On 24 March 2020, the FFA announced that the 2019–20 A-League season would be postponed until further notice due to the COVID-19 pandemic in Australia and New Zealand,[2] and subsequently extended indefinitely.

[13] Adelaide United played their first pre-season friendly for the season on 16 July, against North Eastern MetroStars, which resulted in a 3–1 victory.

[14] A week later, the club played an intra-club friendly, with the senior squad beating the youth side 1–0, with Nathan Konstandopoulos scoring the only goal.

[19] Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.

Adelaide United Goal of the Month award winners were chosen via open-access polls on the club's official website.