25 year old Harding joined Town from Leeds in the summer of 2006, but found himself surplus to requirements at Portman Road in the 2008/9 campaign, which he spent the last few months of on loan at fellow Championship side Reading.
Harding is the ninth player to be told he can leave the club, with Matt Richards, Ivan Campo, Tommy Miller, Dean Bowditch, Billy Clarke, Kurt Robinson, Jai Reason and Chris Casement already having left Portman Road.
Alex Bruce has signed a new deal with the club, whilst Ed Upson and Shane Supple are set to sign new deals in the coming days. Liam Trotter is the only remaining out of contract player who still is scheduled to meet with Town boss Roy Keane to discuss his future.
Click here for full career stats on Dan Harding.