Lewandowski did not find the net in Bayern's 5-1 win over Eintracht Frankfurt, but still ended the season on top of the league scoring charts with 22 goals to his name.
The Polish striker previously got his hands on the "goalscorer's cannon" in 2014, 2016 and 2018, and is now one of only four players to have won the prize four times or more.
The record holder remains legendary Bayern striker Gerd Mueller, who was top scorer seven times in his Bundesliga career.
"It is an honour for me to be behind such a legend, I still have a way to go to catch him," said Lewandowski.