The knockout phase involved 32 teams: 20 teams which received a bye, and the 12 teams which advanced from the qualifying round. Below are the 32 teams which participated in the knockout phase.
Bracket
Format
Each tie in the knockout phase, apart from the final, was played over two legs, with each team playing one leg at home. The team that scores more goals on aggregate over the two legs advanced to the next round. If the aggregate score was level, the away goals rule was applied, i.e. the team that scoredmore goals away from home over the two legs advanced. If away goals were also equal, then extra time was played. The away goals rule was again applied after extra time, i.e. if there were goals scored during extra time and the aggregate score was still level, the visiting team advanced by virtue of more away goals scored. If no goals were scored during extra time, the tie was decided by penalty shoot-out. In the final, which was played as a single match, if the score was level at the end of normal time, extra time was played, followed by penalty shoot-out if the score remained tied. The mechanism of the draws for each round is as follows:
In the draw for the round of 32, the sixteen teams with the highest UEFA club coefficients were seeded, and the other sixteen teams were unseeded. The seeded teams were drawn against the unseeded teams, with the seeded teams hosting the second leg. Teams from the same association or the same qualifying round group could not be drawn against each other.
In the draw for the round of 16, the eight teams with the highest UEFA club coefficients were seeded, and the other eight teams were unseeded. The seeded teams were drawn against the unseeded teams, with the order of legs decided by draw. Teams from the same association could not be drawn against each other.
In the draws for the quarter-finals and semi-finals, there was no seeding, and teams from the same association could be drawn against each other. As the draws for the quarter-finals and semi-finals were held together before the quarter-finals were played, the identity of the quarter-final winners was not known at the time of the semi-final draw. A draw was also held to determine which semi-final winner was designated as the "home" team for the final.
On 17 July 2014, the UEFA emergency panel ruled that Ukrainian and Russian clubs would not be drawn against each other "until further notice" due to the political unrest between the countries.
The first legs were played on 12 and 13 September, and the second legs on 26 and 27 September 2018.
Matches
Zürich won 6–1 on aggregate. ---- Fiorentina won 4–0 on aggregate. ---- Ajax won 4–1 on aggregate. ---- Lyon won 7–0 on aggregate. ---- Rosengård won 3–0 on aggregate. ---- Brøndby won 3–2 on aggregate. ---- Chelsea won 11–0 on aggregate. ---- Atlético Madrid won 3–1 on aggregate. ---- VfL Wolfsburg won 3–0 on aggregate. ---- Slavia Praha won 7–0 on aggregate. ---- Barcelona won 4–3 on aggregate. ---- Glasgow City won 2–1 on aggregate. ---- Bayern Munich won 11–0 on aggregate. ---- Paris Saint-Germain won 6–1 on aggregate. ---- Linköping won 10–1 on aggregate. ---- LSK Kvinner won 4–0 on aggregate.
Round of 16
The draw for the round of 16 was held on 1 October 2018, 13:00 CEST, at the UEFA headquarters in Nyon, Switzerland.
Seeded
Unseeded
Overview
The first legs were played on 17 and 18 October, and the second legs on 31 October and 1 November 2018.
Matches
Bayern Munich won 5–0 on aggregate. ---- VfL Wolfsburg won 10–0 on aggregate. ---- Lyon won 13–0 on aggregate. ---- Barcelona won 8–0 on aggregate. ---- Paris Saint-Germain won 5–2 on aggregate. ---- Chelsea won 7–0 on aggregate. ---- Slavia Praha won 3–2 on aggregate. ---- LSK Kvinner won 3–1 on aggregate.
Quarter-finals
The draw for the quarter-finals was held on 9 November 2018, 13:00 CET, at the UEFA headquarters in Nyon, Switzerland.
Overview
The first legs were played on 20 and 21 March, and the second legs on 27 March 2019. During the Chelsea - PSG tie a number of arrests were made by the Metropolitan Police of travelling supporters of PSG who were arrested for possession of illegal drugs, weapons and vandalism. This was after disorder was reported at Waterloo and WimbledonTrain stations and a bus carrying PSG supporters being searched and barred entry to Kingsmeadow Stadium.
Matches
Bayern Munich won 6–2 on aggregate. ---- Barcelona won 4–0 on aggregate. ---- Lyon won 6–3 on aggregate. ---- Chelsea won 3–2 on aggregate.
Semi-finals
The draw for the semi-finals was held on 9 November 2018, 13:00 CET, at the UEFA headquarters in Nyon, Switzerland.
Overview
The first legs were played on 21 April, and the second legs on 28 April 2019.
Matches
Lyon won 3–2 on aggregate. ---- Barcelona won 2–0 on aggregate.
Final
The final was played on 18 May 2019 at the Groupama Arena in Budapest. The "home" team for the final was determined by an additional draw held after the quarter-final and semi-final draws.