Real Madrid are La Liga champions after a 2-0 victory at Malaga rendered Barcelona's 4-2 comeback success against Eibar irrelevant.
With Real Madrid needing only a point to secure the title, Cristiano Ronaldo settled any nerves with the opening goal inside two minutes.
Real Madrid's party mood was heightened by news that Barcelona had fallen two goals behind against lowly Eibar, before Karim Benzema doubled the advantage at Malaga.
An own-goal got Barcelona back in the game, before Luis Suarez levelled matters and a Lionel Messi double secured victory.
But it mattered little as Real Madrid celebrated a 33rd league title and their first in five years.
Diego Simeone confirmed he will stay on as Atletico Madrid head coach after the club said farewell to the Vicente Calderon with a 3-1 win over Athletic Bilbao.
The Argentinian coach has been linked with a number of clubs, most notably former side Inter Milan, who are under new, wealthy ownership.
However, Simeone insisted "I am staying here" when asked about his future after the victory.
"I am going to stay because this club has a future and the future is all of us together," he added.
Juventus have become the first club to win the Serie A title six years in a row by beating Crotone 3-0.
Even though Roma closed to within a point of the leaders with victory at Chievo on Saturday night, success in this penultimate fixture of the season saw Juve retain the Scudetto.
On his 31st birthday, Croatian striker Mario Mandzukic banished any fears about an afternoon of struggle with the opening goal, and Paulo Dybala eased any latent jitters with a well-taken second.
With time running out, midfielder Alex Sandro added gloss to the scoreline as Juve wrote a new page in the history of Italian football.
Elsewhere, in Germany champions Bayern Munich finished their campaign with victory over Freiburg.
Arjen Robben, Arturo Vidal, Franck Ribery and Joshua Kimmich all scored in a 4-1 win, which means Carlo Ancelotti's side finished 15 points clear of Leipzig. Nils Petersen netted the consolation goal.
It also marked the final game for captain Philipp Lahm and Xabi Alonso before retirement.