The knockout phase involves the 16 teams which qualify as winners and runners-up of each of the eight groups in the group stage. Each tie in the knockout phase, apart from the final, is played over two legs, with each team playing one leg at home. The team that scores more goals on aggregate over the two legs advance to the next round. If the aggregate score is level, the away goals rule is applied, i.e. the team that scored more goals away from home over the two legs advances. If away goals are also equal, then thirty minutes of extra time is played. The away goals rule is again applied after extra time, i.e. if there are goals scored during extra time and the aggregate score is still level, the visiting team advances by virtue of more away goals scored. If no goals are scored during extra time, the tie is decided by penalty shoot-out. In the final, which is played as a single match, if scores are level at the end of normal time, extra time is played, followed by penalty shoot-out if scores remain tied. The mechanism of the draws for each round is as follows:
In the draw for the round of 16, the eight group winners are seeded, and the eight group runners-up are unseeded. The seeded teams are drawn against the unseeded teams, with the seeded teams hosting the second leg. Teams from the same group or the same association cannot be drawn against each other.
In the draws for the quarter-finals onwards, there are no seedings, and teams from the same group or the same association can be drawn against each other.
Qualified teams
Bracket
Round of 16
The draw for the round of 16 was held on 11 December 2017, 12:00 CET. With five English teams in the round of 16, this was the first time five teams from one association qualified for the Champions League knockout phase.
Summary
The first legs were played on 13, 14, 20 and 21 February, and the second legs were played on 6, 7, 13 and 14 March 2018.
Matches
Juventus won 4–3 on aggregate. ---- Manchester City won 5–2 on aggregate. ---- Liverpool won 5–0 on aggregate. ---- Sevilla won 2–1 on aggregate. ---- Real Madrid won 5–2 on aggregate. ---- 2–2 on aggregate. Roma won on away goals. ---- Barcelona won 4–1 on aggregate. ---- Bayern Munich won 8–1 on aggregate.
Quarter-finals
The draw for the quarter-finals was held on 16 March 2018, 12:00 CET.
Summary
The first legs were played on 3 and 4 April, and the second legs were played on 10 and 11 April 2018.
Matches
4–4 on aggregate. Roma won on away goals. ---- Bayern Munich won 2–1 on aggregate. ---- Real Madrid won 4–3 on aggregate. ---- Liverpool won 5–1 on aggregate.
The first legs were played on 24 and 25 April, and the second legs were played on 1 and 2 May 2018.
Matches
Real Madrid won 4–3 on aggregate. ---- Liverpool won 7–6 on aggregate.
Final
The final was played at the NSC Olimpiyskiy Stadium in Kiev on 26 May 2018. The "home" team was determined by an additional draw held after the semi-final draw.
