Martin, 40, has signed a three-year deal with the Foxes, who were relegated from the Sky Bet Championship last season following a points deduction for breaching the EFL’s financial rules.
He said: “I’m delighted to be here and excited to begin working with the players and staff. This is a club with great history, strong support and high expectations, and I’m looking forward to getting to know the club, the city and the supporters.
“My immediate focus is on the team: building strong relationships, setting clear standards and creating performances that Leicester City supporters can connect with and be proud of.”
Leicester’s chief football officer Jon Rudkin said Martin’s appointment followed a “thorough process” and is in no doubt the former Scotland defender is a “strong leader” who can “help us move forward with purpose and direction.”
After impressing at Non League Lewes in 2004, he joined Wycombe that summer and spent four years at Adams Park, playing 142 games and scoring five goals.
His time in South Buckinghamshire saw him help the Chairboys reach the League Two play-off semi-finals in both 2006 and 2008, as well as the League Cup semi-finals in 2007.
He would spent the next 18 months at Peterborough United, before joining Norwich City in January 2010, helping the Canaries win back-to-back promotions from League One to the Premier League.
Martin would spent the next eight years in Norfolk before having a brief loan spell at Rangers in 2018, which led to permanent move to Walsall that summer.
He ended his playing career at Wycombe’s Buckinghamshire rivals Milton Keynes, helping them win promotion to League One in 2019.
That year, we would become the club’s manager, before stints at Swansea City, Southampton, Rangers and now Leicester City soon followed.