2023–24 LEN Euro Cup

The 2023–24 LEN Euro Cup is the 32nd edition of the water polo competition organised by the Ligue Européenne de Natation (LEN). This is the first season under the new changes made by LEN.

The defending champions are A-Híd Vasas Plaket, but they were eliminated by Jug AO Dubrovnik in the eight-finals.

The winners were Jug AO Dubrovnik, who defeated Primorje Erste Bank Rijeka 12–6 in an all-Croatian final.

Format
36 teams (14 from Champions League and 18 starting in this competition) will compete in this tournament. The 36 teams are divided into eight groups, four with five clubs and four with four teams. The groups are held in one country, where the top 2 in every group advances to the group stage. For the first time ever, the group stage will be played in a home and away system. Like the previous round, the top 2 progresses into the knockout stage. The 8 teams left, plus the 8 teams that were eliminated at the Champions League main round, go into the knockout stage. There will be eighth-finals, quarter-finals and a final four competition to decide the champions.

Rankings
Starting this season, LEN also started a club rankings. Excluding the teams eliminated from the Champion League, only countries ranked in the top 12 can enter a maximum of three teams in the Euro Cup.

Draw
The draw was on 11 September 2023. H indicates which club is hosting the groups. Teams in bold advanced to the group stage. The seeding was decided by as follows:
 * The new LEN club rankings.
 * LEN country club rankings.
 * LEN men's national team rankings (although not applied).

Group stage
The draw took place on 26 September 2023 in Barcelona, Spain. The top 2 from every group advances to the 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.

This is the first time that this round is being held in a home and away format. Nine countries are being represented, with Italy boasting the most clubs with four.

Seeding
The eight teams in pot 1 won their group in the qualification round, while the 8 runners-up in the qualification round are in pot 2.

Quarter-finals
The draw took place in Barcelona on 26 March 2024. There was no seeding.

Final four
The final four was held at the Bazeni Kantrida in the Croatian city, Rijeka. The city was given the hosting rights on 2 May 2024. Originally, NC Vouliagmeni won the hosting rights, but after they were eliminated, Primorje Erste Bank Rijeka, backed the Rijeka government, decided to file an application. Primorje Erste Bank Rijeka paid LEN 40,000 Euros in order to organise the event.

Bracket
 