Former Argentina defender Pochettino has managed Espanyol, Tottenham and PSGChelsea have agreed terms to make former Tottenham boss Mauricio Pochettino their new manager.
He will join the club in the summer, with Frank Lampard remaining as interim manager until the end of the season.
Pochettino, who has also managed Southampton, has been out of work since Paris St-Germain replaced him with Christophe Galtier in summer 2022.
The 51-year-old Argentine managed Spurs for five years from 2014 and led them to the 2019 Champions League final.
Pochettino will be Chelsea's sixth permanent manager in five years, following the sacking of Thomas Tuchel and Graham Potter earlier this season.
Lampard took interim charge of the Blues at the start of April following Potter's dismissal.
Chelsea have had a difficult season, losing to Manchester City in the third round of both the FA Cup and League Cup.
They also lost to Real Madrid in the quarter-finals of the Champions League, which ended any viable hopes of them qualifying for Europe next season.
They are currently 11th in the Premier League, having won just one of their past 11 games, losing eight of them.
Pochettino had been linked with a return to Tottenham after they parted company with Antonio Conte in March.
He guided Spurs to the League Cup final in 2015 and a Premier League runners-up spot in 2016-17, with his side missing out on winning both to Chelsea.
Following his stint at Tottenham, Pochettino took over from Tuchel at PSG in January 2021.
The French club finished second in Ligue 1 at the end of the 2021-22 campaign but did win the Coupe de France and the Trophee des Champions, which were the first trophies of Pochettino's managerial career.
Pochettino started his managerial career with Espanyol before his 16-month spell at Southampton.
Pochettino wants a team fans can 'fall in love with' - Balague
In April, Spanish football expert Guillem Balague told BBC's Football Focus that the Argentine was approached in September as a possible replacement for Tuchel, but turned the club down before they appointed Potter.
"It was a different time where I think Chelsea had made up their mind on Potter, and Pochettino sensed that," said Balague.
"Now it feels like the club is ready for him. Before, the fans were missing Tuchel, who won them the Champions League the year before.
"But the fans and the club are wanting him to arrive."
Balague believes Pochettino wants to produce a team Chelsea fans can "fall in love with".
"He wants a team that presses, that is aggressive - he wants players that know they have to fight to get into the starting XI," Balague added.
"He is obviously going to have to trim the squad and those players that stay will have to fight for their place and know that nothing is guaranteed."
