The Polish international, 32, beat off opposition from Manchester City’s midfielder, Kevin De Bruyne, and Bayern team-mate, Manuel Neuer.
The award was announced during the 2020/21 UEFA Champions League group stage draw in Geneva, Switzerland.
The 2019/2020 season was one of the greatest in Bayern’s 120-year history, and no player contributed more to it than Lewandowski.
The Poland striker scored in every game en route to the UEFA Champions League final in Lisbon, picking up 15 goals and six assists as well as the trophy he had targeted for so long.
He also hit 34 goals in 31 Bundesliga matches and six in five German Cup games.
His achievements include: UEFA Champions League winner, Bundesliga winner, German Cup winner and UEFA Champions League top scorer.
Others are: UEFA Champions League Squad of the Season, Bundesliga top scorer and Bundesliga Player of the Season.