He played college football for the Memphis Tigers, and was selected in the first round of the 2016 NFL draft by the Denver Broncos.

Lynch has also been a member of the Seattle Seahawks and Pittsburgh Steelers of the NFL, the Saskatchewan Roughriders of the Canadian Football League (CFL), the Michigan Panthers of the United States Football League (USFL), and the Orlando Guardians and San Antonio Brahmas of the XFL.

[4][5] After redshirting for his freshman year at Memphis in 2012, Lynch was named the Tigers' starting quarterback prior to the 2013 season.

In Memphis' 63–0 victory over SMU, Lynch tied a Football Bowl Subdivision record with seven passing touchdowns in a half.

[24] On October 2, 2016, Lynch played in his first NFL regular-season game against the Tampa Bay Buccaneers, replacing the injured Trevor Siemian.

[25] In Week 5, Lynch started his first NFL game, completing 23 of 35 passes for 223 yards, one touchdown, and one interception in the 23–16 loss to the Atlanta Falcons.

[26][27] In Week 13, Lynch again replaced the injured Siemian against the Jacksonville Jaguars, posting 12 completions on 24 passing attempts for 104 yards in a 20–10 win.

[29] Lynch suffered a shoulder injury against the Green Bay Packers in the team's third preseason game of the 2017 season.

[35] Going into mini-camps for the 2018 season, it was announced that Lynch would serve as backup quarterback, behind the newly acquired Case Keenum.

[36] Two days after the Broncos preseason opener against the Minnesota Vikings, the team announced that Lynch had been demoted to third-string quarterback as Chad Kelly was promoted to backup.

[42] On June 28, 2021, it was announced that Lynch had signed with the Saskatchewan Roughriders of the Canadian Football League (CFL).

[43] He did not dress for games during the season as he was the fourth string quarterback and spent most of the time on the one-game injured list.

[44] On February 22, 2022, Lynch signed with the United States Football League and was selected with the eighth pick of the 12th round of the 2022 USFL draft by the Michigan Panthers.