Rangers sacked manager Michael Beale on Sunday after less than a year in charge of the Glasgow giants.
A 3-1 defeat at home to Aberdeen on Saturday left Rangers seven points adrift of Scottish Premiership leaders Celtic after just seven games.
Beale also failed to qualify for the Champions League in August, losing a playoff to PSV Eindhoven 7-3 on aggregate.
Veteran midfielder Steven Davis will lead an interim management team.
"Results this season have fallen short of what everyone connected to Rangers would expect," the club said in a statement.
"Therefore, the decision was reached today to terminate the contract of the manager, as well as the contracts of coaches Neil Banfield, Damian Matthew, Harry Watling and Jack Ade."
Beale replaced Giovanni van Bronckhorst in November but was unable to prevent Celtic winning a treble of domestic trophies last season.
The Englishman was then allowed to reconstruct his squad this summer, but nine new signings have largely underwhelmed with Rangers losing three of their opening seven league games.
"It is clear that results have fallen well short of the board's, Michael's and our supporters' expectations," said Rangers chairman John Bennett.
"The search process for the new manager is already underway. I wish Steven Davis and the interim management team every success - they will remain in charge for as long as it takes to make the right appointment."
Rangers travel to Aris Limassol in the Europa League on Thursday before facing St Mirren away on Sunday ahead of a two-week international break.
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