This country star's songwriting talents apparently didn't stem from his success in English class, because he's just admitted that he's a high-school dropout.

"I quit school at 15!" he said. "I would've left sooner if I could, but you've gotta legally stay 'til you're 15."

While Keith insisted that "I'm always very careful to not have parents think that I support kids leaving school at a young age," he also said, "The biggest education I got was when I hit the road and got life's education."

CHECK OUT PICS OF KEITH'S "LIGHT THE FUSE" TOUR BELOW!