Pochettino's five-and-a-half-year stint in North London was brought to an end on Tuesday with Spurs languishing in 14th after 12 Premier League games.
And it seems as if chairman Daniel Levy has been lining-up Mourinho as a replacement.
The self-ascribed 'Special One' joins on a contract which lasts until the end of the 2022/23 season.
He will take charge of his first game at Saturday lunchtime when Spurs face London rivals West Ham United.
Mourinho back in management
56-year-old Mourinho is now entering his fourth managerial spell in English football.
He took charge of Chelsea between 2004 and 2007, and again between 2013 and 2015.
In those periods he delivered three Premier League titles, three League Cups and one FA Cup.
But he was sacked in December 2015, just seven months after his third top-flight triumph, following a miserable start to Chelsea's title defence.
Mourinho would then take the reins at Manchester United in 2016.
He would again be dismissed after a 3-1 defeat at the hands of United's archrivals Liverpool, the culmination of increasing concerns about results, style and Mourinho's approach to young talent.
He had publicly criticised the United hierarchy for failing to provide him with what he considered adequate transfer funds in the summer window.
The enigmatic Portuguese, who has also managed at Inter Milan and Real Madrid, has been working a pundit for Sky Sports this season as he looked for a route back into the game.
He reportedly turned down an offer to coach in the Chinese Super League.
Speaking to the official club website, Mourinho expressed his 'excitement' at the prospect of working with Spurs' immensely talented squad.
"I am excited to be joining a Club with such a great heritage and such passionate supporters," he said.
"The quality in both the squad and the academy excites me. Working with these players is what has attracted me."
Levy, meanwhile, stressed his confidence that his new appointment would revitalise the club and bring them a first major honour since 2008.
"In Jose we have one of the most successful managers in football," he 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."