Los Blancos won the Spanish top flight for the 35th time in their history after Rodrygo Goes' brace and goals from Marco Asensio and Karim Benzema ensured they cannot be caught with four games left to play.
As Real Madrid celebrated their latest title triumph, Courtois could not help but take aim at rivals Barcelona, who inflicted a painful 4-0 defeat on Carlo Ancelotti's in El Clasico back in March.
"The key moment came after the Clasico," Courtois explained to Movistar+ following Saturday's victory.
"Some celebrated as if they had just won the title, that they had come back [to our level].
"But we kept our calm to beat Celta in a tough match and then Getafe, who are always difficult opponents.
"La Liga is a team effort. We all attack and defend. That day against Sevilla was crucial, coming back from 2-0 down when everybody thought we were on the floor and that killed our rivals a little."
Real Madrid will turn their attention towards the Champions League semi-final second leg at the Santiago Bernabeu on Wednesday looking to overturn a 4-3 deficit against Manchester City.
"We have had a great year and we hope to finish it off with the Champions League, let's see if we can play another final," Courtois added.
