The Blues have announced the signing of the midfielder who starred under new manager Enzo Maresca in the Championship last season.
Brighton were keen on the 25-year-old Foxes academy graduate before Chelsea struck a £30million deal.
Ahead of the official announcement, Dewsbury-Hall all-but confirmed the transfer on Instagram in a lengthy post to his boyhood club.
“Well what can I say?” he said. “What a journey it’s been. 17 years of my life devoted to this club and it’s been a pleasure. I’ve loved every minute of my time at this football club and created some memories & friendships I’ll never forget.
“When we were relegated in the 22/23 season, I felt personally responsible for my part played in that. I made it my goal to ensure we got back to the Premier League within the first season, as I know how devastating a a position that can be for a club if it doesn’t happen.
“I’m very proud of what we achieved together last season – creating memories of a lifetime for us all. But bigger than that, hopefully going some way to righting the wrongs of that relegation season.
“The overwhelming amount of messages I’ve received in the past few days has honestly touched me and I thank each and every person for taking the time to do so, it means so much to me and my family.
“I want to thank all of the team mates I’ve played with, the coaches that l’ve worked with and fans that l’ve grown with.
“I’m glad I’m leaving the club with them in the Premier League, where they belong, and wish Leicester City all the best in the upcoming season and further on.
“I’m one of your own, Leicester. But it’s time for me to go now…
“Thanks for the ride. KDH.”
The Englishman joined Leicester’s academy at the age of eight and made his debut in January 2020.
He featured 129 times for the Foxes in all competitions and leaves amicably after helping them return to the Premier League.
Dewsbury-Hall was named in the 2023/24 Championship team of the season and won multiple individual awards at the King Power last season.
