"The club can today announce that Mauricio Pochettino and his coaching staff Jesus Perez, Miguel D'Agostino and Antoni Jimenez have been relieved of their duties," Tottenham, who sit 14th in the Premier League, said in a statement.
Pochettino, 47, joined Spurs from Southampton in 2014 and has been instrumental in turning Tottenham into Champions League regulars over the past four seasons.
That culminated in a dramatic run to the club's first ever European Cup final in June, which they lost 2-0 to Liverpool in Madrid.
However, domestically results have been on the decline since February.
Spurs had the faltering fortunes of Arsenal and Manchester United to thank for them clinging onto a top-four finish last season as they won just three of their final 12 league games.
That form has continued at the start of this season with just three wins from their opening 12 games leaving Tottenham already 11 points outside the top four and 20 behind leaders Liverpool.
"We were extremely reluctant to make this change and it is not a decision the board has taken lightly, nor in haste," said Tottenham chairman Daniel Levy.
"Regrettably domestic results at the end of last season and beginning of this season have been extremely disappointing.
"It falls to the board to make the difficult decisions -- this one made more so given the many memorable moments we have had with Mauricio and his coaching staff -- but we do so in the club's best interests."