Paul O'Connell has been an important figure for Munster
Munster were crowned Magners League champions after the Ospreys beat the Dragons but failed to secure a bonus point at the Liberty Stadium.
Having been at or near the top of the table all season, Munster overtook their nearest rivals Ospreys in early January and led since then.
Their second title was secured with the last two rounds of games still to play.
The current Heineken Cup champions previously won the league trophy in 2002-03.
"Munster clearly intended to claim the Magners League trophy this season, following on from their success in Europe last year," said David Jordan, Director of Celtic Rugby.
"From the outset they have been almost unstoppable, having won 13 of their 16 matches to date.
"Munster's success on the pitch has been reflected off it and the re-opening of the impressive Thomond Park Stadium has brought capacity crowds to their Magners League games at that venue.
"The esteem in which their players are held has resulted in the selection of a large contingent of Munster players for the British and Irish Lions touring party named last week.
"The winning of the Magners League title is a splendid achievement and the culmination of a strong and well coached squad throughout the campaign."