Town have parted company with Damien Delaney by mutual consent.
The Republic of Ireland international, who would have been out of contract at Portman Road at the end of the season, joined Blues in the summer of 2009.
He went on to make 105 appearances for the Club, scoring three goals but was in and out of the side last term and has been restricted to a place on the bench this season.
"I have enjoyed my time at Ipswich but it seems the right time to move on,” the 31-year-old defender told the Club website
“I have been here three and a half years now and am probably the longest serving player at the Club but not being in the side made me think about my future and like I said, it’s time for a change.
“I’d like to wish the Club the best of luck for the future.”
Town boss Paul Jewell added: “Damien has been a good servant to the Football Club and we thank him for that and wish him every success.”