Leeds United have confirmed the dismissal of Marcelo Bielsa following a dismal run of form, culminating in a 4-0 defeat to Tottenham on Saturday.
Pressure had mounted on the Argentine manager following a run of just one win in eight matches in all competitions.
In a statement Leeds said: "Leeds United can today confirm the club have parted company with head coach Marcelo Bielsa.
"The 66-year-old was in charge of the team for over three-and-a-half years, having taken the reins in June 2018."
Leeds United chairman Andrea Radrizzani said: "This has been the toughest decision I have had to make during my tenure at Leeds United, taking into account all the success Marcelo has had at the club.
"With Marcelo as our head coach, we had three incredible campaigns and the good times returned to Elland Road. He changed the culture of the club and brought a winning mentality to us all. The moments created, particularly in the 2019/20 season and winning promotion to the Premier League, will of course live long in all our memories, myself and the fans included.
"However, I have to act in the best interest of the club and I believe a change is required now in order to secure our Premier League status. Recent results and performances have not met our expectations.
"We find ourselves in a precarious league position and I feel now is the right time to bring in a new head coach, in order to have an impact in the decisive stage of the season.
"Naturally, myself, along with everyone else at the club would like to thank Marcelo for his efforts and achievements and we wish him the very best for the future."
Director of football Victor Orta added: "Since arriving at Leeds United Marcelo had a huge impact on the club, on a scale I have not seen before.
"He has created a legacy, overseeing major infrastructure improvements at Thorp Arch, uniting the supporters and the players, and giving a clear pathway for young players to transition into the first team.
"It is disappointing his reign has had to end in this manner, given the special times we have enjoyed in recent years, which have been some of the best in my career, but we cannot hide from recent results.
"I would like to thank Marcelo for his commitment and dedication, and I wish him every success going forwards."
The news comes after Leeds were thrashed 4-0 by Tottenham at Elland Road on Saturday, with goals from Matt Doherty, Dejan Kulusevski, Son Heung-min and Harry Kane handing Antonio Conte's side all three points.
The result means Leeds have now conceded 60 league goals this season, 20 of them this month.
Leeds are currently 16th in the Premier League table, although they could drop into the relegation places if Burnley and Everton win their two games in hand.