Nick Montgomery has been “relieved of his duties as head coach”, Hibernian have announced.
The 42-year-old Leeds-born former Scotland Under-21 midfielder had been in charge since September.
But his side missed out on a top-six finish in the Scottish Premiership and slipped to ninth after Saturday’s 4-0 home defeat by Aberdeen.
Some fans staged a sit-down protest following the match at Easter Road, but Montgomery pleaded for patience, pointing out that the club’s owners knew that he needed an overhaul of his squad this summer.
However, in a club statement, The Gordon Family said: “As a board, this was not a decision we made lightly but felt it a necessary one to move the team forward.
“Although Nick and his coaching team worked tirelessly, their efforts didn’t deliver the results we had hoped for.”
It leaves Hibs seeking their sixth permanent team boss in just over four years.
Assistant head coach Sergio Raimundo and goalkeeping coach Miguel Miranda have also left Hibs with immediate effect.
Former captain David Gray steps in for a fourth spell as caretaker manager for the remaining two games of the season, with Motherwell visiting on Wednesday and a visit to bottom side Livingston on Sunday.
Hibs say they will be making “no further comment” at this time.
Montgomery spent most of his playing career with Sheffield United before moving to Australia with Central Coast Mariners and Wollongong Wolves.
Having guided Mariners to the A-League championship in 2023 after his move into management, he was appointed to succeed Lee Johnson as Hibs boss.