The 23-year-old's previous deal with the Bundesliga champions ran until June 2014, but Hummels has now inked a three-year extension to his existing contract.
"We are pleased that a key player like Mats Hummels has signed a new long-term deal. He's not only very important defensively, but plays a key role in our build-up play as well," said sporting director Michael Zorc.
Meanwhile, head coach Jurgen Klopp was equally pleased with the defender's contract extension, as Hummels had plenty of other options.
"Mats Hummels could have joined pretty much every team in Europe, but has opted to stay at Dortmund instead. This is an outstanding development for the club," Klopp commented.
Hummels joined Borussia Dortmund from Bayern Munich in January 2008, and has since become a key player at BVB. The Germany international has made 121 Bundesliga appearances to date, scoring 12 times in the process.