Nick Niemann was born and raised in Sycamore, Illinois where he starred for Sycamore High School under head coach Joe Ryan. As a senior, Niemann was named a first-team all-state and all-conference selection on top of winning the honor of Defensive Player of the Year in the Northern Illinois Big 12 Conference. He also played tight end and was an honorable mention all-conference selection as a junior.
Niemann followed his brother Ben, a current linebacker for the Tennessee Titans, in committing to play for the University of Iowa. Near the end of his career as a Hawkeye, Niemann’s father Jay took a job as the team’s assistant defensive line coach prior to the 2019 season after three seasons calling the defense at Rutgers.