Lehmann coached Australia to two Ashes victories and guided the team to triumph in the 2015 ODI World Cup. Lehmann also led Deccan Chargers to an IPL title in 2009, secured a Big Bash win with Brisbane Heat in 2012-13, and contributed to Queensland's Sheffield Shield victory in 2011-12.

The Australian great accumulated 13,635 runs in the Sheffield Shield—the most in the competition's history—and hit the winning runs in the 1999 ODI World Cup final.

Northamptonshire CEO Ray Payne expressed excitement over Lehmann’s appointment, praising his expertise, leadership, and vision for the club. “We’re thrilled to welcome Darren. His reputation, skills, and track record are unmatched. His philosophy aligns perfectly with our ambitions,” Payne remarked. “With Darren at the helm for the men’s team and David Ripley guiding the Steelbacks Women, Northamptonshire Cricket is positioned for growth and success across the board.”

Lehmann echoed Payne’s optimism, sharing his eagerness to shape a new chapter for the club. "Northamptonshire has a rich history, and I’m excited to help build on that. The players are committed to getting better and making history,” Lehmann said. “I believe we’ll have both success and enjoyment on this journey, and I can’t wait to get started.”

Lehmann will begin his coaching stint in February after the Australian summer, but Lehmann plans to stay connected with the club’s progress throughout the winter, working closely with the assistant coaches to lay a solid foundation. “The pre-season will be a vital time for honing skills and setting the standards we’ll strive for," Lehmann explained. "Our coaches are dedicated to the players’ success, and together we’re focused on reaching new heights, both on and off the field."