Los Blancos beat Liverpool 1-0 in Paris to lift their 14th title.
SportsMail reports the payment is due to a clause in Hazard’s contract when he joined Real Madrid from Chelsea for £103m in 2019, a fee that included performance-related add-ons.
Hazard picked up a winner’s medal despite playing only 83 minutes across the entire competition.
The Belgian has made just three appearances in the club’s Champions League campaign.
He last featured in February in the last-16 first leg loss at Paris Saint-Germain. He only came on for eight minutes.
Before that, Hazard played nine minutes of the 2-0 victory over Inter in Real’s final group game. He only started one match, which was the disastrous 2-1 home defeat against Sheriff Tiraspol in September last year.