After two seasons at Portman Road, the 28 year-old midfielder is being allowed to come off contract.
He posted to X: “My two seasons at Ipswich have been incredibly special.
“The goal when I signed was to help the club return to the Championship, so to do that and then achieve promotion again last season has honestly been a dream come true.
“I’ve met so many wonderful people during my time here and made memories to last a lifetime. I want to thank the fans for their support, all of the coaches and staff I have worked with, and of course my teammates.
“I’ve never been part of a dressing room with the bond we have and I doubt I ever will again.
“I will miss everyone and I wish the club nothing but the best in the Premier League. Come on you Blues.”