The goals were scored by Rodrygo Goes, author of a double (33 and 43), Marco Asensio (55) and Karim Benzema (81).
With four games to go, Real, with 81 points, can no longer be caught by Sevilla (64 points) or FC Barcelona (63 points).
This is the 35th domestic title won by the Merengue club, an absolute record in Spain, far ahead of Barcelona (26 titles) and Atlético de Madrid (10 titles).
Carlo Ancelotti's group thus recovers the Spanish championship crown, lost last season to Atletico Madrid.
A title largely due to the performances of Karim Benzema, top scorer and passer of the Spanish championship, Luka Modric who lives a second youth at 36 years, and Courtois, who saved his team in several decisive games.