2023–24 LEN Champions League

The 2023–24 LEN Champions League is the 61st edition of LEN's premier competition for men's water polo clubs. Because of the congested schedule, there's a new format this year. Pro Recco are the three time defending champions.

FTC-Telekom won their second title after triumphing over Pro Recco in the final.

Format
This season, the format has undergone some changes. After one qualification round (instead of three), sixteen teams will qualify for the group stage. Because of the congested schedule, four groups of four will be played instead of two groups of eight. The top two in each group will make the quarter-finals round (also a group stage). The team that finish third and fourth will compete in the 2023–24 LEN Euro Cup knockout stage. The remaining eight teams in the quarter-finals round will play a further six matches, with the top two in each group making the final four, which makes a return.

Rankings
Starting this season, LEN also started a club rankings. The top 11 best ranked countries in the new rankings are allowed to have their national champion go directly into the main round, as long as they meet requirements.

Teams
Alongside the 11 domestic champions, the defending champions also get a spot in the main round. In the event that the Champions League defending champions won their national league, the runners-up of the national league will take the vacant spot. Although, the Italian runners-up, AN Brescia, declined the spot because they didn't want to pay the wildcard fee (which was 25,000 Euros), their spot went to the Spanish runners-up, Astrapool Sabadell).

Qualification round
The group winners qualify for the main round, while everyone else drops down to the Euro Cup qualifiers.

Draw
The draw was on 10 August 2023. The seeding was decided by the new LEN club rankings. H indicates which club is hosting the groups. Teams in bold advanced to the main round.

Group A
7–10 September 2023, Hannover, Germany

Group B
7–10 September 2023, Kragujevac, Serbia

Group C
8–10 September 2023, Oradea, Romania

Group D
8–10 September 2023, Dubrovnik, Croatia

Main round
The top two from each group make the quarter-finals round. The bottom two from each group drops down to the Euro Cup eighth-finals.

Teams are ranked according to points (3 points for a win, 2 points for a penalty shootout win, 1 point for a penalty shootout loss, 0 points for a loss), and if tied on points, the following tiebreaking criteria are applied, in the order given, to determine the rankings:


 * Points in head-to-head matches among tied teams;
 * Goal difference in head-to-head matches among tied teams;
 * Goals scored in head-to-head matches among tied teams;
 * Goal difference in all group matches;
 * Goals scored in all group matches.

Among the teams, 13 return from last season. Steaua București and Crvena zvezda return after a one season absence, while Jadran Herceg Novi return after a two-season absence. They all replaced Waspo'98 Hannover, Radnički Kragujevac and Genesys OSC-Budapest.

In regards to countries, all 9 from last season return, with the inclusion of Romania and Montenegro after one and two-season absences, bringing the number up to 11.

Quarter-finals round
The eight group winners and eight group runners-up were drawn into two groups, with each one containing two group winners and two group runners-up. The top two teams in each group advanced to the Final Four.

Draw
The draw took place in Barcelona. The seeded and unseeded clubs consist of the teams that finished first and second in the previous round respectively. The only restriction was that clubs from the same group in the Main round could not be drawn against each other.

Teams are ranked according to points (3 points for a win, 2 points for a penalty shootout win, 1 point for a penalty shootout loss, 0 points for a loss), and if tied on points, the following tiebreaking criteria are applied, in the order given, to determine the rankings:


 * Points in head-to-head matches among tied teams;
 * Goal difference in head-to-head matches among tied teams;
 * Goals scored in head-to-head matches among tied teams;
 * Goal difference in all group matches;
 * Goals scored in all group matches.

Final Four
On 18 January 2024, the final four was held in the capital of Malta, Valletta, at the National Pool Complex from the 5 to 7 June 2024.