"At the start of the season, I really didn't think we had a chance of winning the title," said Magath, who will coach Schalke next season. "But I knew we had a good team and we played well and deserved the title."
Bayern and third-place Stuttgart also clinched spots in next season's UEFA Champions League -- for Stuttgart in the qualifying stage.
Magath, who won two Bundesliga titles with Bayern, was doused in champagne by his players at the end of the game.
"It is hard to be leaving now, obviously," added Magath. "I am not quite dry. We were in the locker room and there was quite a bit of champagne flying through the air."