Pep Guardiola's men were rarely troubled after striking twice in the opening 22 minutes through centre-half Dante and midfielder Thiago Alcantara
The German side dominated proceedings throughout and had little difficulty in dispatching Casbalanca - who surprised the likes of Monterrey and Atletico Mineiro en route to the final - to end a magnificent year on a high as world champions, adding the trophy to their Bundesliga, DFB-Pokal, UEFA Champions League and UEFA Super Cup titles.
Pep Guardiola's men broke the deadlock inside the first 10 minutes, with defender Dante turning home from Jerome Boateng's knock down in Marrakech.
And their advantage was quickly doubled midway through the first half as Thiago Alcantara netted with a fine strike from just inside the area.
Casablanca provided more stern resistance in the second half, but Faouzi Benzarti's team never looked like mounting a comeback, with Bayern comfortably holding on to secure their first triumph in an inter-continental competition since their 2001 success in the Intercontinental Cup.
Guardiola made three changes to the side that beat Guangzhou Evergrande 3-0 in the semi-final, with Dante, Xherdan Shaqiri and Thomas Muller all coming in against Casablanca, who named an unchanged team.
Bayern's superiority took only seven minutes to surface as Dante's powerful close-range effort was allowed to stand despite suspicions of offside, the goal coming just after Mouhssine Iajour had gone close at the other end.
The gulf in class was evident throughout the first half, and Bayern should have doubled their lead when David Alaba's tame finish was saved by Casablanca goalkeeper Khalid Askri following excellent build-up play with Muller.
Casablanca proved a threat on the counter but their task was made even harder in the 22nd minute, as Thiago met Alaba's pull-back with a sumptuous finish that flew past Askri and into the top corner.
The Bavarians spurned chances to extend their advantage further as Dante headed over from a corner, before Shaqiri forced Askri into another strong save.
Casablanca almost pulled a goal back in bizarre fashion when goalkeeper Manuel Neuer cleared the ball straight to Chemseddine Chtibi.
However, the midfielder failed to capitalise with a poor effort that flew well wide.
Bayern were denied a penalty shortly before the interval, despite Ismail Benlamalem appearing to bring down Franck Ribery.
Fortune continued to keep Casablanca's faint hopes alive just after the hour as the crossbar kept out Shaqiri's close-range effort.
Casablanca captain Mohsine Moutaouali somehow fired over after Neuer had saved from Vivien Mabide's effort, but that proved to be the last chance of a largely uneventful second half, with Bayern closing the game out to seal the world title 37 years to the day of their maiden inter-continental cup triumph.