John O'Korn was born to Gary and Paula O'Korn in Huntingdon, Pennsylvania. He attended Huntingdon Area High School, where he played quarterback, throwing for 1,018 yards and 10 touchdowns as a sophomore, starting 5 games. As a youth, John was an outstanding baseball and basketball player as well as wrestler, placing in several national tournaments. When his family moved to Fort Lauderdale, Florida, O'Korn attended St. Thomas Aquinas High School. In his first season at St. Thomas Aquinas, he threw for 377 yards, seven touchdowns and three interceptions. The next season, he led the team to the 2012 FHSAA 7A state title with an average of 43 points per game. Throwing for 22 touchdowns with just 4 interceptions and over 2,500 yards. He received scholarship offers from Wisconsin, Louisville, Syracuse, Mississippi State, North Carolina, South Florida, and UCF in addition to Houston.
College career
Houston
2013 season
O'Korn earned the backup position for quarterback during preseason camp behind David Piland. However, he made his first collegiate appearance during the first half of the season opener. He became the quarterback beginning with the 2013 Bayou Bucket Classic against Rice. When Piland announced that he would end his career due to concussions, O'Korn was solidified in the role.
2014 season
O'Korn was the starting quarterback for the first five games of the 2014 season before being benched in favor of Greg Ward Jr. The benching was due to an offensive scheme change due to 2013 Offensive CoordinatorDoug Meacham leaving for same position at TCU.
On February 5, 2015, O'Korn announced that he would be transferring to the University of Michigan. Due to NCAA transfer rules, O'Korn sat out the 2015 season. He spent the 2015 season serving as the scout team quarterback.
2016 season
2016 Spring practice began on February 29 with a highly anticipated quarterback battle between redshirt junior Shane Morris, O'Korn, redshirt sophomoreWilton Speight, true freshman Brandon Peters and redshirt freshman Alex Malzone. As Spring practice wound down in late March, Speight, O'Korn and Morris seemed to be the leading three, but in that order. O'Korn and Speight were the starters in the April 1 Spring game. On September 3 before the opening game against Hawaii, Speight was named as the starting quarterback, despite O’Korn leading the preseason point challenge. O'Korn made his Michigan debut in the third quarter after Michigan had built a 49–0 lead, and he went 3–3 on a touchdown scoring drive. After Speight was sidelined with an unspecified shoulder injury, O'Korn started and led the team to a 20–10 victory over Indiana on November 19. O'Korn posted 7 completions in 16 attempts for a total of 59 yards with no touchdowns or interceptions. The performance represented the lowest passing yardage total for Michigan since John Navarre posted 58 in a November 17, 2001 victory for the 2001 Wolverines against Wisconsin.
2017 season
After another quarterback battle for the starting role, O'Korn entered the 2017 season as Speight's primary backup again and relieved him briefly in the second quarter of the season opener against Florida. After Speight suffered what would become a season-ending injury on September 23 against Purdue, O'Korn became the primary starter. He helped lead the Wolverines to victory against Purdue, but in his first season start of the season in the rivalry game against Michigan State, O'Korn threw three interceptions in a 14-10 loss. Against rival Ohio State, he also threw a costly pick in the fourth quarter with 2:47 left to play which cost the Wolverines the game. After the game, he emotionally blamed himself for the loss, saying with tears falling down his face, "the hardest part for me is just you come here to win this game and our senior class wasn’t able to do it, and you know I hold myself responsible for a lot of that…. I can’t imagine a worse feeling right now"
Statistics
Through the end of the 2017 season, O'Korn's statistics are as follows:
Professional career
After going undrafted in the 2018 NFL Draft, O'Korn was invited to attend the Detroit Lions' rookie camp on a tryout basis, followed by tryouts with the New York Giants and Miami Dolphins.