Tottenham sacked manager Ange Postecoglou on Friday, just over two weeks after he ended the club's 17-year trophy drought by winning the Europa League.
The club said in a statement he had been "relieved of his duties" following a performance review after a poor Premier League season.
But the Australian paid the price for Tottenham's worst domestic season since they were relegated from the top flight in 1976-77.
"Following a review of performances and after significant reflection, the Club can announce that Ange Postecoglou has been relieved of his duties," a statement on Tottenham's official X account said.
Exactly two years after he was hired from Celtic, Postecoglou's eventful spell in north London was brought to a end by chairman Daniel Levy.
Tottenham lost 22 of their 38 Premier League games to finish 17th in the table, above only relegated trio Leicester, Ipswich and Southampton.
"The Board has unanimously concluded that it is in the best interests of the club for a change to take place," the statement said.
"Whilst winning the Europa League this season ranks as one of the club's greatest moments, we cannot base our decision on emotions aligned to this triumph."