The 22-year-old came first in a poll of the ten current Austrian Bundesliga coaches, joining Ivica Vastic as the only other player to have won the award on four occasions.
"I'd like to express a huge thanks to the coaches who voted for me," said Alaba, who beat RB Salzburg duo Jonatan Soriano and Kevin Kampl to win the award. "Of course this is something special for me and I'm absolutely delighted to win."
In 2013, Alaba became the first footballer since Toni Polster to be named the Alpine Republic's Sportsperson of the Year. The full-back has made ten Bundesliga appearances this season, but suffered a knee injury against AS Roma in the UEFA Champions League which ruled him out until the new year.
Since making his first-team debut in 2010, Alaba has made a total of 113 German top-flight appearances for Bayern and TSG 1899 Hoffenheim.