Republic of Ireland internationals Stephen and Noel Hunt have not had their contracts renewed by Ipswich.
Winger Paul Anderson, midfielder Darren Ambrose and loanee Richard Chaplow are all also now without a club.
However, manager Mick McCarthy has not ruled out future deals in the summer.
"I have not closed the door on those players," he told the club website. "We might be good for them and they might be good for us but there is nothing happening with them at the moment."
Former Wolves forward Stephen Hunt, 33, played 19 times this season, while brother Noel, 32, scored twice in eight games after joining from Leeds in November.
Chaplow was on a season-long loan from Millwall, but his contract with the fellow Championship club has ended.
McCarthy added: "There is an element of freshening things up. We need to go again and you need fresh faces to do that so we will see what happens with those lads."
Ipswich missed out on reaching the Championship play-off final following a 3-1 second-leg semi-final defeat by local rivals Norwich on Saturday.
Only Anderson featured in both play-off semi-final matches against the Canaries, coming on as a 31st-minute replacement for the injured Luke Varney in the first leg and starting the second.
McCarthy confirmed that defender Elliott Hewitt and forward Jack Marriott, both 20, have been released by the club.