MLB Star Andrew McCutchen -- I LOOOOOVE Honey Boo Boo!!!

Pittsburgh Pirates superstar Andrew McCutchen loves Honey Boo Boo. HE LOVES IT. And he's not afraid to admit it.

McCutchen -- who recently signed a 6-year, $51.5 MILLION contract with the Pirates -- was strollin' through L.A. Live yesterday ... at the same time a Carrie Underwood concert was going on.

McCutchen swears he wasn't at the Underwood show (though he says he is a fan) ... but fessed up about his obsession with the "Honey Boo Boo" show.