The five-star picked the Vols over Arizona.
"I'll be spending the next few years at Tennessee," said McKenzie on Thursday.
McKenzie's father, Reggie and his uncle, Raleigh, both played for the Vols.
The West's No. 1 prospect, McKenzie was named the DL MVP of The Opening, having a stellar week and making a big push to be named the nation's top prospect in the 2015 class.
Kahlil McKenzie Highlights from The Opening: