Real Madrid start a third consecutive defence of their UCL crown against Roma, CSKA Moscow and Viktoria Plzen in the group stage.
The draws, handled by Real and Atletico Madrid players, Kaka and Diego Forlan respectively, placed the 13-time champions in the same group as Roma, the slayers of Barcelona last season.
Barcelona, who have won their group in the last 11 seasons, will come up against Tottenham of England, PSV of Holland and the 2010 champions, Inter Milan.
In arguably the group of death, Liverpool, beaten finalists last season, will slug it out with Paris Saint-Germain of France and Napoli of Italy, coached by former Chelsea manager, Carlo Ancelotti.
Floundering Manchester United were drawn in Group H alongside Juventus, meaning a replay of the 1999 semi-final, and a return to Old Trafford for Cristiano Ronaldo.
The group stages begin on September 18 and 19, while the final will be played on June 1, 2019, at Atletico Madrid’s new Wanda Metropolitano Stadium.
Full group stage draw
Group A: Atletico Madrid, Borrusia Dortmund, AS Monaco, Club Brugge
Group B: Barcelona, Tottenham Hotspur, PSV Eindhoven, Inter Milan
Group C: Paris Saint-Germain, SSS Napoli, Liverpool, Red Star Belgrade
Group D: Lokomotiv Moscow, FC Porto, Schalke 04, Galatasaray SK
Group E: Bayern Munchen, Benfica, Ajax Amsterdam, AEK Athens
Group F: Manchester City, Shakhtar Donetsk, Olympic Lyon, Hoffenheim
Group G: Real Madrid, AS Roma, CSKA Moscow, Viktoria Plzen
Group H: Juventus, Manchester United, Valencia, Young Boys