At Adel High School, Kinnick led the football team to an undefeated season, and then he scored 485 points for the basketball team, leading them to the district finals. After his junior year of high school, the Kinnick family moved when Nile Kinnick Sr. took a job in Omaha, Nebraska. Nile was a first-team all-state selection in both football and basketball as a senior, as he started for one year with his brother Ben at the Benson High School in Omaha. He led Benson to a third-place finish in the state basketball and to the city baseball championship.