55 teams from 46 UEFA member associations participated in the 1997–98 UEFA Champions League. The 1997–98 competition was expanded from previous seasons. The groups was increased to six. The runners-up in the 8 higher tier leagues - England, France, Germany, Italy, Netherlands, Portugal, Spain, Turkey - also entered the UEFA Champions League. As current UEFA Champions League titleholder, Borussia Dortmund automatically qualify for this season's competition. As they did not finish in the top 2 in the Bundesliga, Germany had 3 representatives.
The 1997-98 competition had 2 qualification rounds to reach the group stage.
The 30 lower tier domestic champions played a home and away knockout round.
The 15 winners from 1st Qualifying joined the 8 mid tier domestic champions and 8 higher tier domestic runners-up, playing a home and away knockout round. With the admission of Borussia Dortmund required the Turkey champions, Galatasaray to also play in this round.
The 6 group winners and the 2 best runners-up advanced to the knockout stage.