The Buffalo Bills continue reshaping their coaching staff under rookie head coach Joe Brady, adding a key defensive piece to the puzzle. According to NFL Network Insider Ian Rapoport, the team has hired Jim Leonhard—formerly the Denver Broncos assistant head coach and defensive pass game coordinator—as their new defensive coordinator.
Leonhard joins recently hired offensive coordinator Pete Carmichael Jr. as Brady’s top coaching lieutenants. At 43, Leonhard is a fast-rising figure in the coaching world, having spent two seasons with the Broncos as a defensive backs coach and pass game coordinator in 2024 before earning an assistant head coach title in 2025.
A 10-year NFL veteran, Leonhard played four seasons with the Bills starting in 2005 as an undrafted safety. He now returns to Buffalo to help the team reach its Super Bowl aspirations, bringing both NFL playing experience and a strong defensive coaching pedigree.
During his tenure with the Broncos, Leonhard helped guide the team to the 2025 AFC Championship Game, highlighted by a Divisional Round overtime win over the Bills themselves. Now, he will step into an NFL defensive coordinator role for the first time, replacing Bobby Babich, who served as Buffalo’s defensive coordinator over the past two seasons. Leonhard will also inherit responsibilities previously handled by former head coach Sean McDermott, who directed portions of the team’s defensive play-calling.
Leonhard’s experience extends beyond the NFL. He served as Wisconsin’s defensive coordinator from 2017–2022, acting as the team’s interim head coach in his final season. His work developing elite defensive talent, including 2024 AP NFL Defensive Player of the Year Patrick Surtain II, has earned him recognition around the league. Under his guidance, the Broncos posted the No. 2 total defense in 2025, boosting his profile as a coordinator candidate.
Prior to choosing Buffalo, Leonhard also interviewed for defensive coordinator positions with the Dallas Cowboys, Los Angeles Chargers, and New York Jets. Ultimately, he opted to return to the city where he began his NFL career and where he now seeks to make an impact from the sidelines.
With Leonhard handling the defense and Carmichael Jr. leading the offense, Brady has assembled a coaching tandem he hopes will propel the Bills to contend at the highest level in 2026 and beyond.
