Johnson, a junior at Brownsburg High School in Indiana, had previously committed to Tennessee in August, becoming the first commitment in the Vols’ 2017 recruiting class.
Johnson changed his mind after visiting Clemson on Friday, making him the fourth commit Tennessee has lost this month.
“Myself and my family both just felt like it was the right spot for me,” Johnson told 247Sports. “I felt like I had a connection there when I went there. It wasn’t something I was seeking out. I felt confident with my earlier decision of Tennessee at the time, but once I got there it felt right to me.”
At Brownsburg High School this season, Johnson passed for 2,545 yards and 31 touchdowns. As a sophomore in 2014, he threw for 1,434 yards and 10 touchdowns, while completing 54% of his passes.
Johnson, who also had offers from Alabama, Florida, Nebraska, North Carolina, Oklahoma and several others, is the third commitment in Clemson’s 2017 recruiting class. He’s ranked by Scout as the No. 40 player and No. 4 quarterback in the class of 2017.