Jose Mourinho’s Spanish champions will face off with English champions and heavily financed Manchester City.
Dutch champions Ajax are also in Group D and face Real at the group stages for the third successive season. Meanwhile, German champions Borussia Dortmund conclude the group, which is arguably the most eye-catching of the eight this season.
Barca, who lost in the semi-finals of the competition last season, tackle Benfica and Unai Emery’s Spartak Moscow, two sides who finished as runners-up in their respective leagues last term.
Completing Group G is Celtic, a team that the Blaugrana have met twice before in the competition, the last meeting being in the 2007-08 edition at the Last 16 stage.
Malaga, meanwhile, who are in the competition for the first time in their history, face tests against Milan, Zenit and Anderlecht for a place in the Last 16.
The six matchdays are scheduled to be played from the midweek of September 18/19 across to December 4/5.
Full Champions League draw
Porto, Dynamo Kiev, Paris Saint-Germain, Dinamo Zagreb
Milan, Zenit St Petersburg, Anderlecht, Malaga
Real Madrid, Manchester City, Ajax, Borussia Dortmund
Bayern Munich, Valencia, Lille, BATE
Barcelona, Benfica, Spartak Moscow, Celtic
Manchester United, Braga, Galatasaray, Cluj