Coman initially joined Bayern on a two-season loan from Juventus in 2015 but converted the move into a permanent transfer worth €28 million in April.
The France international had signed with Bayern to 2020, but after a strong individual start to the new campaign, and with the team now dominant atop the table under coach Jupp Heynckes, he was rewarded with fresh terms on Thursday.
Coman's new six-year deal comes the same day as the signing of Sandro Wagner from Bundesliga rivals Hoffenheim on a two-and-a-half-year contract, a transfer that was completed for a reported fee of €13m.
Kingsley #Coman : "I'm delighted to be able to carry on playing for this club for many years to come. I feel very much at home at #FCBayern and in Munich." #MiaSanMia #Coman2023 pic.twitter.com/o0pI9wqa2n— FC Bayern English (@FCBayernEN) December 21, 2017
Coman has made 15 Bundesliga appearances this season, scoring two goals, to help Bayern establish an 11-point lead at the top of the table.
The 21-year-old, who started his career at Paris Saint-Germain, made a substitute appearance as Bayern signed off for the winter break with a 2-1 DFB-Pokal defeat of rivals Borussia Dortmund on Wednesday.
Coman, seen as the likely heir to 34-year-old compatriot Franck Ribery, is thrilled to have agreed a new Bayern deal.
"I am very happy and satisfied that I will play for this club for a long time," Coman said. "I feel very comfortable at Bayern and in Munich."