This is the fifth season win for Button in six races from the pole position. Rubens Barrichello finished second. He moved past Ferrari's Kimi Raikkonen at the start to settle an uneventful race in the principality.
Raikkonen managed to finish third for Ferrari's first podium and team-mate Felipe Massa came fourth. It was the best result for Ferrari, who are threatening to quit F1 over a budget cap row, as they finally came alive in a difficult season.
Button who received the trophy from Prince Albert II said, " It is a very special moment to win here in Monaco." "This victory is massive for us at this part of the season," he added.
Button has 51 points from six of 17 races, while Barrichello bagged 35.