Real Madrid were crowned champions of La Liga for the 36th time after Barcelona suffered a 4-2 defeat by Girona.
Carlo Ancelotti's side eased to a 3-0 win over Cadiz earlier on Saturday, which meant the Catalan club had to win at the Estadi Montilivi.
Barcelona led 2-1 at half-time, but three second-half goals from Girona left Real with an unassailable lead at the summit with four matches of the season remaining.
England midfielder Jude Bellingham has been a key figure in Real's success, having scored 18 goals in 26 La Liga games in his first season with the club.
Bellingham posted on X, external "CAMPEONES!!! HALA MADRID Y NADA MAS!!!" which translates as "Champions!!! Go Madrid and nothing more!!!".
The 20-year-old joins Laurie Cunningham (1979–80), Steve McManaman (2000–01 and 2002–03), David Beckham (2006-07) and Kieran Trippier (2020-21) as Englishmen to win La Liga.
Los Blancos have lost just one league game this season and could potentially finish the campaign with 99 points, which would be their second-highest total ever.
It is Ancelotti's second La Liga title as Real coach, having previously won it in 2021-22.
Real have now won nine more titles than the 27 held by Barcelona.
The 14-time European Cup winners face Bayern Munich at the Bernabeu on Wednesday in the second leg of their Champions League semi-final, having drawn 2-2 at the Allianz Arena.
Source: BBC