Barca's title was confirmed with victory at Deportivo La Coruna.
"Very happy, winning this league brings great joy," hat-trick ace Messi remarked.
"We know how tough it is to win LaLiga. That's why we have to value it and celebrate it properly with all our people.
"It was a very special title for all of us because we are yet to lose any matches. We have had difficult moments and we overcame them without knowing the feeling of defeat and that is incredible.
"We were very superior to our rivals and we lost almost no matches [in all competitions], only one in the Copa del Rey and unfortunately the one in Rome, where we had a very unexpected result."