The Buffalo Bills have hired Jim Leonhardt as their new defensive coordinator, sources say. Leonhardt, a former undrafted walk-on safety out of Wisconsin who went on to play four NFL seasons (compiling 431 tackles and 14 interceptions), returns to Buffalo’s staff after two seasons with the Denver Broncos as defensive passing game coordinator and recently serving as assistant head coach under Sean Payton.
Leonhardt first made his mark on the sideline at his alma mater, where he was Wisconsin’s defensive coordinator from 2017–2022 and finished the 2022 season as interim head coach. During his time with the Badgers the defense ranked among the nation’s top 20 in scoring defense five of six years and inside the top 10 on four occasions. He joined the Broncos staff before the 2024 season, also coaching the defensive backs corps that included All-Pro cornerback Patrick Surtain II.
NFL Network’s Ian Rapoport reports Leonhardt interviewed with the Chargers and Ravens this cycle before agreeing to lead a Bills defense that has struggled against the run, ranking 28th and giving up 136.2 rushing yards per game, while allowing 21.5 points per contest (12th fewest) this season. He replaces Bobby Babich, who had been Buffalo’s defensive coordinator in 2024–25 under head coach Sean McDermott; McDermott was dismissed after the Bills’ turnover-plagued 33–30 divisional-round loss to the Broncos.
Jim Schwartz’s departure also coincides with a coaching shakeup in Buffalo’s top job: Joe Brady was promoted from offensive coordinator to head coach earlier this week. Brady, 36, has been on the Bills’ staff since 2022 and is assembling his own staff, which includes former Broncos senior offensive assistant Pete Carmichael Jr. as offensive coordinator—Carmichael reunites with Payton after a long tenure as the New Orleans Saints’ offensive coordinator and previously worked with Brady when Brady was an offensive assistant with the Saints in 2017–18. Sean Payton praised Brady’s promotion and expressed support for the new staff members joining him in Buffalo.
Fan take: This hire matters because Buffalo is explicitly addressing a major postseason weakness—stopping the run—and bringing in a coach with a proven college track record and recent NFL experience could help close that gap. If Leonhardt can translate his success developing defenses (and DBs) at Wisconsin and in Denver to the Bills, it could meaningfully impact Buffalo’s playoff prospects and influence coordinator hiring trends around the league.
