While in Lakeville Mitch Leidner led Lakeville South High School to a 15-7 mark during his junior and senior seasons and he helped the Cougars win the 2010 section championship as a junior when he passed for 2,096 yards and 17 touchdowns. He followed by passing for 1,872 yards and 20 scores as a senior. Leidner was twice named honorable mention all-state, and he was all-conference in basketball as a junior.

The Star Tribune reported in 2011 that Leidner’s performance in a 7-on-7 passing tournament led to a scholarship offer from the University of Minnesota. Leidner played for former head coaches Jerry Kill and Tracy Claeys during his time with the Golden Gophers. He finished his college career second in school history in completions (580) and attempts (1,029), third in passing yards (7,287) and fifth in passing touchdowns (36).

Leidner is the only quarterback in Gophers history to pass and rush for 30 or more touchdowns. His 33 rushing touchdowns are the most in school history by a quarterback, and his 1,495 rushing yards are the third-most by a quarterback. Leidner appeared in 47 games and started 41. He went 24-17 as a starter.