The Dutch international's previous deal at the Allianz Arena was due to expire in June 2015.
However, the former Chelsea winger has now agreed to remain with the German and European champions until the summer of 2017.
"I'm delighted we've now signed the new contract and I'll continue pursuing trophies with FC Bayern. I'm now in my fifth season in Munich and there will be three more after this," the 30-year-old told the club's official website.
"There can be no better indication of how happy my family and I feel to be here and how much I enjoy playing for this club and with this team. I'm looking forward to the years ahead and to plenty more trophies with FC Bayern."
Robben has scored 10 goals from 20 Bundesliga outings this season.