The 2018–19 UEFA Champions League was the 64th season of Europe's premier club football tournament organised by UEFA, and the 27th season since it was renamed from the European Champion Clubs' Cup to the UEFA Champions League.
On 9 December 2016, UEFA confirmed the reforming plan for the UEFA Champions League for the 2018–2021 cycle, which was announced on 26 August 2016. As per the new regulations, the previous season's UEFA Europa League winners will qualify automatically for the UEFA Champions League group stage (previously they would qualify for the play-off round, but would be promoted to the group stage only if the Champions League title holder berth was vacated, although this promotion to the group stage had been made in all three seasons since it was established from 2015–16). Meanwhile, the top four teams from the leagues of the four top-ranked national associations in the UEFA country coefficients list will qualify automatically for the group stage as well. Only six teams will qualify for the group stage via the qualification rounds, down from ten in the previous season.