2012–13 LEN Champions League
The 2012–13 LEN Champions League is the 50th edition of LEN's premier competition for men's water polo clubs. It ran from 14 September 2012 to 1 June 2013, and it is contested by thirty teams from eighteen countries. There will be no defending champion as Pro Recco renounced to the competition for disagreements with the FIN on the number of allowed foreign players in the Italian clubs' squads. Runner-up Primorje Rijeka, former champions Mladost Zagreb and Vasas Budapest, Italy's CN Posillipo and any team from Montenegro also declined to take part in the competition. The Final Four took place on May 31 and June 1 in Belgrade.
Qualification round
| Key to colors in group tables |
| Progress to the Preliminary Round |
Group A ([Tbilisi])
Group B ([Kreuzlingen])
Preliminary round
Group A
Group B
Group C
Group D
Top 16
The draw was held on 28 February 2013 in Rome, Italy. The first legs were played on 9–10 March, and the second legs were played on 20–21 March 2013.Quarterfinals
The draw was held on 25 March 2013 in Rome, Italy. The first legs were played on 17 April, and the second legs were played on 30 April and 1 May 2013.Final Four ([Belgrade])
, Belgrade, SerbiaSemi-finals
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Third place
Final
Final standings
| Team | |
 Crvena zvezda | |
 Jug Dubrovnik | |
 Atlètic-Barceloneta | |
| Partizan |