David Villa put Barca ahead in the third minute before Cesc Fabregas added the second 10 minutes later, with Martin Montoya firing home a stunning volley as Barcelona went 3-0 up inside 16 minutes.
Andres Iniesta added the fourth following a quick counter-attacking move early in the second half before Malaga substitute Pedro Morales pulled one back for the visitors.
The result means Barcelona finish the season as champions with 100 points, matching Real Madrid's title-winning record of last season, while Malaga end their campaign in a Europa League qualifying spot.
David Villa opened the scoring early on when Iniesta played the ball into the box and Pedro laid the ball square to the striker, who slotted it home with ease.
Fabregas added the second in the 14th minute when he picked the ball up on the left wing, dinked it back inside and played a one-two with Iniesta, before firing the ball past Malaga goalkeeper Caballero Willy from the edge of the area.
Montoya then fired a stunning 20-yard strike into the bottom corner from the right of the area from Xavi's inswinging corner as Barcelona well and truly stamped their authority on the game.
Gerard Pique missed the chance to add the fourth when he put a free header wide with just over five minutes of the first half still to play.
Malaga came close to pulling a goal back early in the second half when Julio Baptista forced Barca keeper Jose Pinto to parry the ball, with Morales pouncing on the rebound and forcing Jordi Alba to clear off the line.
However, the visitors were left to rue what might have been when Barca counter-attacked from the clearance which resulted in Iniesta launching the home side's fourth from outside the area.
Malaga did pull one back four minutes later, though, when defender Jesus Gamez curled a perfectly-weighted ball in from the right wing and it dropped perfectly for Morales, who volleyed it home from close range.
Both sides squandered further chances in a high-tempo second half as Barcelona ran out comfortable winners.