Leicester have decided to end Craig Levein's tenure as manager of the club because of the side's poor league form.
Levein has failed to turn around Leicester's fortunes
The Foxes are in the Championship's bottom three after one win in 15 League games, and backroom staff Peter Houston and Kenny Black will also leave.
Leicester created an FA Cup third-round upset when they beat Tottenham but their poor league form has continued.
Assistant manager Rob Kelly and goalkeeping coach Mike Stowell will take temporary charge of the club.
Leicester executive director Tim Davies said: "It is with huge disappointment that we have to announce the departure of Craig, Peter and Kenny.
"I would like to thank them for the work they have done for the club since their arrival in November 2004."
Davies added that many of the club's long-term objectives in terms of reducing the squad's average age and operating on a more sound financial footing had been achieved by Levein.
But he stated the club's perilous position in the Championship was behind Levein's exit.
"Our league position is unacceptable and we need to make a change.
"We have had great support from our fans and all of us have one common goal, to avoid relegation and we see this as the way forward to do this."
Levein believes the young squad he has built at the Walkers Stadium resulted in the club's inconsistent form but that he has laid the foundations for future success.
He said: "We came down to Leicester in November 2004 and, with the full co-operation of the board of directors, embarked upon a long-term strategy to reduce the wage bill, reduce the average age of the team and build the foundations for the long term success of Leicester City.
"We felt we were making significant progress in those areas and our success in reaching the quarter-finals of the FA Cup last season and in beating Tottenham earlier this month seemed to bear that out.
"Also, with the introduction of players such as Richard Stearman, Patrick McCarthy and Stephen Hughes, among others, we feel the club has some valuable assets upon which the future can be built.
"However, we knew that with such a young squad, consistency would be difficult to achieve and we understand the board has taken the view that the results were causing them major concern and have taken the decision to terminate our contracts.
"We wish the club every success in the future and are certain that the club will reap the benefits from the work we have put in."