The Portuguese is back in the Premier League after he was sacked by Manchester United in December 2018, after a poor run of form at the Old Trafford.
Pochettino guided the Lilywhites to their first Champions League final back in May, but a poor start to the season have seen Tottenham win only three matches from their first 12 league matches of the season, currently sitting 14th on the league table.
"I am excited to be joining a club with such a great heritage and such passionate supporters," Mourinho said in a club statement following his appointment.
"The quality in both the squad and the academy excites me. Working with these players is what has attracted me."
The Chairman of Tottenham Hotspurs Daniel Levy admitted that it was hard sacking Pochettino, but insists the club’s interest is paramount.
Levy added that, with the appointment of Mourinho, a man who is a serial winner, and having won three Premier League titles, they hope he will bring ‘energy and belief in the dressing’.
"In Jose we have one of the most successful managers in football," Levy said.
"He has a wealth of experience, can inspire teams and is a great tactician. He has won honours at every club he has coached.”
"We believe he will bring energy and belief to the dressing room.”
The 56-year-old’s first game will be at the London Stadium on Saturday as Tottenham travel to take on London rivals West Ham in the Premier League.
