King died on Thursday in Las Vegas at the age of 89, according to the Associated Press.
Obama famously sang "Sweet Home Chicago" with King at an event at the White House in February 2012. You can watch a clip of that moment above.
Read Obama's full statement on King below:
The blues has lost its king, and America has lost a legend. B.B. King was born a sharecropper’s son in Mississippi, came of age in Memphis, Tennessee, and became the ambassador who brought his all-American music to his country and the world. No one worked harder than B.B. No one inspired more up-and-coming artists. No one did more to spread the gospel of the blues.
Three years ago, Michelle and I hosted a blues concert at the White House. I hadn’t expected that I’d be talked into singing a few lines of “Sweet Home Chicago” with B.B. by the end of the night, but that was the kind of effect his music had, and still does. He gets stuck in your head, he gets you moving, he gets you doing the things you probably shouldn’t do – but will always be glad you did. B.B. may be gone, but that thrill will be with us forever. And there’s going to be one killer blues session in heaven tonight.