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

The 2023–24 LEN Challenger Cup was the 2nd edition of a water polo competition organised by the Ligue Européenne de Natation. It acts as the third tier, below the LEN Champions League and the LEN Euro