The 51-year-old Argentine, who returns to the Premier League following previous spells in charge of Tottenham and Southampton, permanently succeeds Graham Potter, who was dismissed at the start of April after less than seven months in charge.

Frank Lampard, who led Chelsea on a caretaker basis until the end of the season following Potter's sacking, has left the club.

Jesus Perez, Miguel d'Agostino, Toni Jimenez and Sebastiano Pochettino will form part of Pochettino's coaching staff at Stamford Bridge.

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Chelsea's co-sporting directors Laurence Stewart and Paul Winstanley said: "Mauricio's experience, standards of excellence, leadership qualities and character will serve Chelsea Football Club well as we move forward.

"He is a winning coach, who has worked at the highest levels, in multiple leagues and languages. His ethos, tactical approach and commitment to development all made him the exceptional candidate."

Owners Todd Boehly, Behdad Eghbali, Jose E. Feliciano, Mark Walter and Hansjorg Wyss added: "The sporting team conducted a diligent and thoughtful process that the board is proud of. We are delighted that Mauricio will be joining Chelsea. Mauricio is a world-class coach with an outstanding track record. We are all looking forward to having him on board."

Sky Sports News understands Pochettino was the unanimous first choice of the board and the club. The club carried out an exhaustive process - but wanted to speak to the former Tottenham boss from the outset.

In all discussions, it is believed Pochettino was "fully on board" with the structure of the club - including working with co-sporting directors Stewart and Winstanley.

Despite spending £600m in the last two transfer windows, Chelsea finished 12th in the Premier League - the first time they finished in the bottom half for 27 years.

The Blues ended the season without a trophy and will not play in Europe next season.

Pochettino had been out of work since being sacked by Paris Saint-Germain last summer after 18 months in charge of the French side, having guided them to the Ligue 1 title in 2022 and the French Cup the year before.

The former Espanyol boss managed Spurs for five years from May 2014, following an 18-month spell at Southampton.

Pochettino was unable to end Spurs' long wait for a trophy but he did lead them to the 2019 Champions League final, which they lost to Liverpool.

Pochettino also took Spurs to the 2015 League Cup final and to a second-place finish in the 2016/17 Premier League season, with Chelsea winning both competitions.

Neville: Poch the right fit for Boehly's Chelsea

Sky Sports pundit Gary Neville feels Pochettino is the right man to take charge on a permanent basis at Stamford Bridge given the profile of players Chelsea have signed.

"Based on what [Chelsea co-owner Todd] Boehly has said, Chelsea have done their spending for the next three years - apart from signing a centre-forward," Neville told Sky Sports in April.

"If they appointed Zinedine Zidane, Luis Enrique or Diego Simeone, they're going to want to have another £300m as they won't like some of the players they've previously signed.

"They'd got to appoint a manager who is going to inherit and like the squad that they've got - a lot of them are young - and I think that man is Mauricio Pochettino."

Move makes sense - but neither party can afford failure

Sky Sports' Joe Shread:

While Mauricio Pochettino will no doubt be excited to return to the Premier League and Chelsea will be delighted to have secured a manager of his pedigree, there is a lot riding on the Argentine's appointment - for both parties.

Unusually for a manager whose previous Premier League stint ended with him being sacked by Tottenham nearly four years ago, Pochettino's stock remains high in the top flight, with Spurs' regression since his exit helping to explain why.

But while the 51-year-old is rightly praised for the work he did at Spurs, culminating in their first Champions League final in 2019, he ultimately failed to bring any long-awaited silverware to north London during his five-year spell in charge - the kind of record that won't be tolerated at Chelsea.

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Pochettino did end his personal trophy drought at Paris Saint-Germain, winning the French Cup in 2021 and Ligue 1 a year later, but he was also sacked by the French giants and has been out of work since last summer.

That's a long time for an elite coach to be away from the day-to-day of club management, while the fact that Unai Emery was still at Arsenal and Frank Lampard had only just begun his first spell in charge of Chelsea at the point of Pochettino's Spurs exit shows how long he has been away from the Premier League.

The pressure on Pochettino is clear - but it weighs even heavier on the shoulders of his new employers. Since their takeover last summer, Todd Boehly and Behdad Eghbali have overseen one of the most chaotic and unsuccessful seasons in Chelsea's recent history.

After seeing their decision to sack Champions League-winning head coach Thomas Tuchel and replace him with Graham Potter spectacularly backfire, the owners need Pochettino - who will be the fifth person to take charge of a Chelsea match in less than 12 months - to justify their faith.

Boehly and Eghbali cannot afford any more damage to their credibility. Chelsea supporters will not take another season of mediocrity, while the financial concerns caused by a continued absence from the Champions League cannot be overlooked.

Pochettino - a manager with a proven track record in the Premier League - makes sense for Chelsea, while the Blues' young and talented squad would appear to suit the manager.

The potential upsides for both parties are clear - but neither can afford for this partnership to fail.

'Pochettino to Chelsea is quite surreal'

Sky Sports News' Paul Gilmour:

"It is quite surreal with it being a manager, certainly in English football, who is associated with Tottenham, Chelsea's rivals.

"Mauricio Pochettino knows that he will have a big job on his hands at Chelsea with rebuilding. The squad is huge, the numbers need to come well down.

"We also heard Harry Kane talk a few weeks ago about the values that were created under Pochettino and that is something that he has as his biggest strength. He knows how to bring a group of players together. He is very much a people person, somebody who can galvanise and work with what he has got.

"Chelsea have spent a large amount of money but he will have money to spend. You would expect him to tweak and add further strength in certain positions."