A total of 76 teams from 52 UEFA associations (Liechtenstein organises no domestic league competition) participated in the 2008–09 Champions League. Countries are allocated places according to the 2007 UEFA league co-efficientranking. The spot reserved for the title holder was not used since Manchester United qualified for the group stage as the Premier League (Association 2) champions.
Below is the qualification scheme for the 2008–09 Champions League:
Associations 1–3 (Spain, England and Italy) each have four teams qualify
Associations 4–6 (France, Germany, and Portugal) each have three teams qualify
Associations 7–15 (Romania, Netherlands, Russia, Scotland, Ukraine, Belgium, Czech Republic, Turkey, and Greece) each have two teams qualify
Associations 16–53 (except Liechtenstein) each have one team qualify
Teams entering in this round
Teams advancing from previous round
First qualifying round
28 champions from associations 25–53
Second qualifying round
8 champions from associations 17–24 (Switzerland, Norway, Israel, Serbia, Denmark, Austria, Poland and Hungary)
6 runners-up from associations 10–15
14 winners from the first qualifying round
Third qualifying round
6 champions from associations 11–16
3 runners-up from associations 7–9 (the Netherlands enter the winners of a series of play-off games rather than the runners-up automatically qualifying)
On 4 June 2008, a decision was taken to exclude Portuguese champions Porto from this year's competition, after the club was found guilty of bribing referees in the Portuguese Liga during the 2003–04 season. As a result, Vitória Guimarães were promoted from the 3rd qualifying round to the group stage and Benfica from the UEFA Cup into the 3rd qualifying round. However, after Porto appealed the decision, the decision was referred by UEFA's Appeals Body back to the Control & Disciplinary Body for re-assessment. The meeting to re-assess the situation took place on 16 June 2008, with the decision being reversed and Porto being allowed back into the 2008–09 Champions League. The decision was taken due to Porto's disciplinary process in Portugal not yet being complete.
Bulgarian champions CSKA Sofia were excluded from the tournament having failed to secure a UEFA licence due to the club being in debt to various government bodies and creditors.Levski Sofia took their place in the 3rd qualifying round.
The draw for the first and second qualifying rounds was held on Tuesday, 1 July 2008 in Nyon, Switzerland. The first leg matches were held on 15 July and 16 July, while the second legs were played on 22 July and 23 July 2008.
In the draw for the first qualifying round, teams were divided into two pots, on the basis of UEFA coefficients. The lower pot contained the 14 teams from associations 40–53: none of these teams had a team ranking.
In the draw for the second qualifying round, teams were divided into two pots, on the basis of UEFA coefficients. The higher pot contained teams ranked 166 or higher: so each tie contained exactly one team ranked in the top 166.
The draw for the third qualifying round took place on 1 August 2008 in Nyon, Switzerland. The first leg matches were played on 12 August and 13 August, while the second leg matches took place on 26 August and 27 August. The losing team of each match are being seeded into the 2008–09 UEFA Cup first round; while the winning teams advance into the UEFA Champions League 2008–09 group stage.
In the draw for the third qualifying round, teams were divided into two pots, on the basis of UEFA coefficients. The higher pot contained teams ranked 61 or higher. However, the draw was held before the second qualifying round was played, which meant that Kaunas and BATE Borisov effectively moved into the higher pot, replacing the teams they eliminated.
The top two teams in each group advanced to the knockout stage, and the third-placed teams entered the round of 32 of the UEFA Cup. Based on paragraph 6.05 in the UEFA regulations for the current season, if two or more teams are equal on points on completion of the group matches, the following criteria are applied to determine the rankings:
higher number of points obtained in the group matches played among the teams in question;
superior goal difference from the group matches played among the teams in question;
higher number of goals scored away from home in the group matches played among the teams in question;
superior goal difference from all group matches played;
higher number of goals scored in all group matches played;
higher number of coefficient points accumulated by the club in question, as well as its association, over the previous five seasons.
From the first knockout round through to the semi-finals, clubs play two matches against each other on a home and away basis with the same rules as the qualifying rounds applied. In the last 16, group winners play runners-up other than teams from their own pool or nation. For the draw of the quarter-finals and semi-finals clubs are seeded based on the results in the group and first knockout stage of the current season (eight matches).
The draw for the first knockout round was held on Friday, 19 December 2008 in Nyon, Switzerland. The draw was conducted by UEFA General Secretary David Taylor, Giorgio Marchetti, UEFA's director of professional football and Bruno Conti, the ambassador for the final in Rome.
The draws for the quarter-finals and semi-finals were both held on Friday, 20 March 2009 in Nyon, Switzerland. The draw was conducted by David Taylor and Bruno Conti. Unlike the first knockout round, teams from the same group or country may be drawn together from the quarter-finals onwards.
The first legs of the first knockout round were played on 24 and 25 February 2009, and the second legs were played on 10 and 11 March.
Bayern Munich defeated Sporting CP by 12–1 on aggregate in the first knockout round; the biggest two-leg win in Champions League era.
Manchester United's 2–0 victory against Internazionale in the first knockout round was their 21st consecutive undefeated match, a record surpassing Ajax's 20 undefeated matches, set between 1985–86 and 1995–96. The record was extended to 25 matches, ending with a 2–0 defeat to Barcelona in the final.
The first leg matches were played on 7 April and 8 April, with the second leg matches being played on 14 April and 15 April 2009. Due to the 20th anniversary of Hillsborough Disaster, Liverpool were granted their request that their return leg not be played on 15 April; the match was played on 14 April.
Porto's 1–0 loss to Manchester United in the second leg of the quarter-finals was the club's first ever home defeat to English opposition.
The first leg matches were played on 28 April and 29 April, while the second leg matches were played on 5 May and 6 May 2009. As in 2007–08, the semi-final teams consisted of three Premier League sides and Barcelona. This was the third consecutive season in which three of the four semi-final teams were English.
Manchester United were the first defending champions to reach the semi-finals since the introduction of the first knockout round in the 2003–04 season.
The 2009 UEFA Champions League Final was played at 20:45 CEST on 27 May 2009 at the Stadio Olimpico in Rome, Italy. Barcelona won the match 2–0, with goals from Samuel Eto'o and Lionel Messi. Barcelona's victory also meant that they became the first Spanish team to win The Treble. Manchester United were the first defending champions to reach the final of the competition since Juventus in 1997, but they failed to become the first club to defend the European Cup since Milan in 1990.