Mullen is best known now as the successful head coach of the Mississippi State University football program, but before working with Heisman finalists and guiding the Bulldogs to the top of the college football landscape, he was a two-year starting tight end for the Bears and a first team All-Centennial Conference selection in 1993.
Mullen has spent the past eight seasons at Mississippi State, where he has taken the program to new heights in guiding the Bulldogs to a 61-42 overall record and seven consecutive bowl appearances. Following the magical 2014 season, in which Mississippi State ascended to the No. 1 national ranking, Mullen received the Maxwell Football Club's National Coach of the Year award and was named Associated Press SEC Coach of the Year.
Mullen graduated from Ursinus with a bachelor's degree in Exercise and Sports Science before moving on to Wagner College, where he served as wide receivers coach and connected with current Bears head coach Pete Gallagher, a graduate assistant at the time.
Following stints at Syracuse (1998), Notre Dame (1999-00), and Bowling Green (2001-02), Mullen spent two seasons as quarterbacks coach at Utah, where he developed NFL standout Alex Smith into a Heisman Trophy finalist. From 2005 to 2008, he was the offensive coordinator and quarterbacks coach at Florida, helping to lead the Gators to two national championships and molding Tim Tebow into a Heisman Trophy winner.
Mullen was hired as the UNLV Head Football Coach on December 12, 2024.
Mullen and his wife Megan created the Mullen Family 36 Foundation, which has raised more than $325,000 for charity in the last four years; thirty-six was Mullen's playing number at Ursinus.