The Argentine faces the daunting task of reviving the struggling club, which finished 12th last season. Pochettino will return premier league four years after being sacked by Tottenham.
Pochettino, 51, will take over from caretaker boss Frank Lampard on July 1.
“Mauricio is a world-class manager with an exceptional track record. We are all looking forward to having him on board,” Chelsea co-owners Todd Boehly and Behdad Eghbali said in a statement.
Pochettino, who favors a pressing and attacking style of play, has earned a reputation for favoring young talent and led Southampton to an eighth-place finish in his first full season in England before joining Spurs in 2014.
The 51-year-old will be tasked with reviving Chelsea’s fortunes.
The London club won the Champions League in 2021 but finished that season without silverware and stumbled to their worst campaign since 1993-94 – when they finished 14th under Glenn Hoddle – despite huge spending from their new American owners into players.
Pochettino is Chelsea’s third permanent manager since they were sold in 2022 to a consortium led by LA Dodgers co-owner Todd Boehly and backed by private equity firm Clearlake Capital.
At the time of Lampard’s appointment, co-controlling owners Boehly and Behdad Eghbali said the former Chelsea midfielder had been brought in on an interim basis so the club could carry out a “thorough and comprehensive process” to hire a permanent manager.
Chelsea have lost eight of their 11 games under Lampard, finishing 12th in the table and without European football for next season after their Champions League quarter-final exit.
(With contributions from Reuters)