Barcelona will face seven-time winner AC Milan in the Champions League for the third straight season, while Bayern Munich begins the defence of its title in a group containing Manchester City.
Thursday’s draw in Monaco put Barcelona in Group H with Milan, Ajax and Celtic - four teams who have been European champions 16 times between them.
Barcelona and Milan were grouped together in 2011-12 and then met in the quarterfinals, before facing each other in the round of 16 last season. Barcelona won three of the six encounters and drew two of them.
“You never get easy groups in the Champions League,” Barcelona forward Lionel Messi said. “Of course we know Milan well and we also played Celtic last season, while Ajax have a lot of European history. So we’re looking forward to some very tough, very exciting, very beautiful games.”
Celtic claimed a shock 2-1 victory over Barcelona last year’s group stage.
“I think it’s the best and the worst draw we could have got,” Celtic manager Neil Lennon said. “In terms of glamor, it doesn’t come any better but it’s the most difficult we could have got.”
Bayern, which beat Borussia Dortmund 2-1 last year’s final at Wembley Stadium, is in Group D along with City, CSKA and Viktoria Plzen.