The three-star middle linebacker from John Ehret (Marrero, La.) High chose Arkansas over offers from Arizona State, Memphis and Oregon, among others.
"I have a better relationship with the defensive coaching staff and Coach (Bielema)," Harris said. "I felt like Arkansas wanted me more than Oregon."
A week after the Razorbacks' annual Red-White spring game, Harris told Scout that he came really close to committing to Arkansas then, but decided to wait.
"Ever since then, I've been thinking about it," Harris said. "Right before my high school team's spring practice, I told some people I'd make a decision soon and now I'm ready."
He is the third 2016 pledge from the state of Louisiana, with the other three being in-state recruits.
Two-star quarterback Cole Kelly (Teurlings Catholic) and three-star defensive tackle Briston Guidry (Archbishop Rummel) are the other two Louisiana commits.
"By us three committing, I think we can get some more from Louisiana," Harris said. "I know I'm trying to get some more."
As a junior, Harris made 82 tackles, 15 tackles for loss, three forced fumbles, two fumble recoveries and three pass deflections.