Jose Mourinho, who had been subject to speculation that he will leave for the Premier League, is able to boast of overcoming the dominance of Barcelona by winning Real Madrid's first title since 2007-2008.
Gonzalo Higuain started the scoring with a 16th minute strike from just outside the box to put Real Madrid ahead, following a missed penalty kick by Cristiano Ronaldo in the 12th minute. Ronaldo's shot was blocked by the feet of goalkeeper Gorka Iraizoz.
Four minutes after Higuain's goal, playmaker Mesut Ozil knocked in a shot off an excellent cross from Ronaldo to give Los Galacticos the 2-0 lead.
Ronaldo would head in the third goal of the match off a Xabi Alonso cross, to give Real Madrid the comfortable lead on the road.
Real Madrid took 18 shots with 10 on goal, while Athletic Bilbao took 11 shots, with two on target. Possession belonged to Athletic Bilbao, who controlled the ball for 51 percent of the match.
The win extended Real Madrid's unbeaten streak to 21 league matches.
The title is another major accomplishment for Mourinho, who adds another piece of silverware to his resume after Los Galacticos defeated Barcelona in Copa del Rey last season. Mourinho now becomes the first coach to win a league title in four different leagues: Portugal, England, Italy and Spain.
Here are the highlights of Athletic Bilbao - Real Madrid: