Johnson attended Brownsburg High School in Brownsburg, Indiana. During his career he passed for 6,657 yards and 69 touchdowns, including 2,233 yards and 25 touchdowns as a senior. Johnson was a four-year starter on the varsity football team, playing in the state's largest class. He led his team to a Hoosier Crossroads Conference championship as a senior and was awarded the team's MVP. Johnson was named team captain his junior and senior years. He holds multiple school records including: Most touchdown passes completed in a game, season, most passing yards in a game and in a career. Johnson received IFCA and AP all-state honors as a junior and a senior, and was the #1 ranked player in the state of Indiana throughout high school. He was an Indiana Griddy Award Winner. Johnson was also an all-state track runner while at Brownsburg HS, running the 200, 400, and the 4×400 meter relay. He is part of the school's record-holding 4×400 team with a time of 3:17.81. In December 2016, Johnson was named Indy Star's Mr. Football.
Recruiting
Johnson was rated as a five-star recruit and was ranked among the top recruits in the 2017 class. Johnson was ranked by Rivals.com as the number 18 overall player in the nation, and was the 2016 Rivals 5-star challenge quarterback MVP. He committed to the Tennessee Volunteers football in 2015 after taking multiple visits there. However after a visit to Clemson University in December 2015 he flipped his commitment to Dabo Swinney's Clemson Tigers. Johnson is a 2016 Elite 11 quarterback, and as such he was chosen to compete in Nike's The Opening. While there he made the All-Nike Rating Team with a score of 122.04. Johnson won the Pete Dawkins Trophy as the MVP of the 2017 US Army All-American Bowl.
Johnson was an early enrollee at Clemson. Johnson did not redshirt his freshman year at Clemson. He began the season as 3rd string quarterback, but earned the backup position by mid season. Johnson saw limited action against Kent State, Louisville, Wake Forest, Georgia Tech, The Citadel, Miami, and South Carolina. He threw his first collegiate touchdown to tight end Cannon Smith during Clemson’s game against Wake Forest. Johnson completed 77.8 percent of his passes, throwing for 234 yards and 2 touchdowns during the 2017 season. On June 11, 2018, Johnson announced that he would transfer to Northwestern University.
Northwestern
Johnson sat out the 2018 season and will be eligible to play in 2019. Jonhson's first season at Northwestern was described by many as a huge disappointment. Johnson struggled with injuries, bad play and serious family struggles off the field. Johnson completed 46% of his passes, throwing for 432 yards, one touchdown and 4 interceptions.
