The 26-year-old midfielder has put pen to paper on a contract until 2028.
Advertisement
Advertisement
With just one more year left on his Leicester contract, Maddison leaves the club after a five-year spell.
He was part of the Foxes' FA Cup-winning campaign in 2020/21.
A graduate of Coventry's academy, Maddison played for Aberdeen and Norwich before arriving at Leicester in 2018.
An England international on three occasions, he was in the Three Lions' squad for the 2022 World Cup.