In the first all-German final, Borussia Dortmund plays Bayern Munich later Saturday in European football's showpiece match.
"It's very important for German football that two of our teams are in the final," 27-year-old Dortmund fan Peter Moffe said outside Wembley.
Yellow Dortmund shirts were ubiquitous on the north London streets around the stadium and in Trafalgar Square in the hours before the game amid a low-key security operation, three days after a British soldier was killed in south London on Wednesday.
On Friday, the official Champions League final dinner was disrupted by three people infiltrating a London venue to protest to UEFA President Michel Platini about the under-21 European Championship being hosted by Israel next month.
UEFA described the incident as a "minor disturbance" and said three arrests were made, although police said only two people were detained.
"A 24-year-old-man and a 24-year-old woman evaded private security at the UEFA Champions League celebrity party, being held at Billingsgate Market in the City of London, and managed to reach the stage and launch a protest," City of London Police said in a statement. "They were quickly ejected from the event by the private security and the event organizers made a complaint to the City of London Police. Shortly after both were arrested on suspicion of aggravated trespass and assault and are currently being held in custody."
The force said it is continuing to investigate "the circumstances of the incident."