After college, Campbell stayed within Ohio and took a job as a graduate assistant at
Bowling Green State University from 2003 to 2004. While at Bowling Green
Scott Pioli, then the director of player personnel for the
New England Patriots, offered Campbell an interview for a job at the team, but Campbell declined.
Toledo Toledo promoted Campbell to offensive coordinator in 2010. Toledo made Campbell the permanent head coach at the end of 2011 when Beckman departed for the
University of Illinois. He was 32 years old and the youngest head coach in the
Football Bowl Subdivision. Two weeks into the job,
Toledo defeated
Air Force in the
Military Bowl. Campbell coached four full seasons at Toledo: 2012–2015, amassing a record of 35–15. Campbell was named the
Big 12 Coach of the Year twice. In his
second year, Campbell led Iowa State to an 8–5 season that included wins against 3
Oklahoma and 4
TCU. Iowa State won their bowl game that year against the
Memphis Tigers in the
Liberty Bowl. During his
third year at
Iowa State, he led the Cyclones to a second 8–5 season. This included a 6–3 record in Big 12 play, their most conference wins in history. In 2018, Campbell was reportedly requested for an interview for the
New York Jets NFL team, however, he declined the interview. In the pandemic-shortened 2020 season, Campbell led the Cyclones to their best season in decades. The Cyclones finished in first place in the Big 12, their first regular-season first-place finish of any sort in 119 years. However, they lost the Big 12 title game to
Oklahoma. They were selected for the
2021 Fiesta Bowl, the first major-bowl appearance in school history, and defeated 25
Oregon 34–17. They finished ninth in both major polls, the highest final ranking in school history. On February 8, 2021, Iowa State announced a new contract extension for Campbell through the 2028 season. It was reported that Campbell was offered an eight-year, $68.5 million deal by the
Detroit Lions for their head coaching position in 2021, but other reports said that the Lions never put an offer on the table. On September 28, 2024, Campbell passed
Dan McCarney to become the winningest coach in school history with a shutout victory over
Houston. Additionally in 2024, the program got off to its best start since 1938 and reached 11 wins for the first time ever by winning the
2024 Pop-Tarts Bowl against 15
Miami (FL) in a 42–41 win. This bowl game win marked the fourth time in the season that Iowa State got a winning score with less than two minutes remaining. On August 1, 2025, Campbell finalized a contract extension through the 2032 season. He followed this up with a season-opening win over 17th ranked
Kansas State, who was the favorite to win the Big 12, in the Aer Lingus College Football Classic in
Dublin,
Ireland. This marked Campbell's 100th career victory as a head coach.
Penn State On December 5, 2025, Campbell agreed to become the next head coach at
Pennsylvania State University. He replaced
James Franklin, who was fired earlier in the season. ==Head coaching record==