Town have confirmed that manager Paul Jewell has left the club "by mutual consent".
A statement from the Blues reads: "Ipswich Town Football Club have today parted company with Paul Jewell by mutual consent.
"Jewell, who has been in charge at Portman Road since January 2011, finalised matters with club owner Marcus Evans and chief executive Simon Clegg this morning and all parties agreed that he should leave his post as manager."
Owner Marcus Evans added: "Since he first walked through the door here, no one has worked harder to bring success to this football club than Paul Jewell.
"Unfortunately his outstanding commitment has not been rewarded by results on the pitch and having spoken with Paul at length, we feel it’s best for him and the club if we go our separate ways.
"I’m bitterly disappointed — as is Paul — that it has not worked out as we had hoped when he became our manager 21 months ago and I would like to put on record my thanks for his services to the club and wish him every success in the future.”
Jewell himself said: "I could not have had any more support than I have done from Marcus Evans and Simon Clegg. I have enjoyed working with both of them in my time as Ipswich Town manager.
"We all know that football is a results business though and I’ve never hidden from the fact that our results have not been good enough.
"It’s been a privilege to be manager of such a fantastic football club and I want to thank the staff and the supporters for the backing they have given me in my time at the club and wish Ipswich Town the best of fortunes ahead.”
Chief executive Simon Clegg said: "I am bitterly disappointed that we have parted company with Paul, but we accept that this is in our respective best interests.
"Paul has worked tirelessly to try and deliver the levels of success on the pitch which we all aspire to but the recent results and our position in the table required us to make a change.
"The search for a new manager of this football club is well under way and I am confident that we will find the right man to get the best out of the players, both individually and collectively, and lead the team to future success.
"The immediate focus is to ensure we secure three points on Saturday and in this regards I have asked Chris Hutchings to take over as caretaker manager.”
Town have called a press conference with chief executive Simon Clegg for 3pm.