Don King -- Undergoes Kidney Surgery ... Get These Stones Outta Me!

Legendary boxing promoter Don King is recovering from kidney stone surgery ... TMZ Sports has learned.

A rep for the World Boxing Commission confirmed King was hospitalized ... after doctors located several kidney stones in the 83-year-old's body.

We're told he's recovering at the hospital -- surgery went well and he's doing fine.

King was recently out in public to speak at an event at Howard University on March 28th and seemed fine.