By SABC Sport
6th April 2023
The 44-year-old previously managed the Blues from July 2019 until January 2021, when he was replaced by Thomas Tuchel.
His surprise return to Stamford Bridge comes after Tuchel's successor, Graham Potter, was dismissed on Sunday with the club in the bottom half of the Premier League.
"We are delighted to welcome Frank back to Stamford Bridge," Chelsea co-controlling owners Todd Boehly and Behdad Eghbali said in a statement.
"Frank is a Premier League Hall of Famer and a legend at this club.
"As we continue our thorough and exhaustive process for a permanent head coach, we want to provide the club and our fans with a clear and stable plan for the remainder of the season.
"We want to give ourselves every chance of success and Frank has all of the characteristics and qualities we need to drive us to the finish line.
"We are all going to give Frank our full backing as we aim to get the best possible outcome from all our remaining games."
Former Chelsea and England midfielder Lampard had been out of a job since January when he left relegation-threatened Everton after less than a year in charge.
Chelsea have nine Premier League games remaining this term, starting with Saturday's trip to Wolves, which is followed by the first leg of their Champions League quarter-final tie with European champions Real Madrid.
Lampard watched from the stands on Tuesday evening as a Blues side managed by caretaker boss Bruno Saltor started the post-Potter era with a goalless draw against Liverpool.
The west London club sit 11th in the table following that result, 14 points adrift of the top four, despite having spent more than £550m on new players this season.
With Lampard installed for the short-term, Chelsea will continue their pursuit of Potter's permanent replacement.
According to reports, one potential front-runner for the full-time job, ex-Spain coach Luis Enrique, flew into London on Wednesday to meet with club officials.
In-demand German Julian Nagelsmann, sacked recently by Bayern Munich, is also thought to be a contender.
Lampard guided Chelsea to the 2020 FA Cup final, which ended in a 2-1 loss to Arsenal, during his previous managerial spell at the club, having joined from Derby.
He led them to 44 wins from 84 matches but picked up five defeats in his final eight league games, as many as in the previous 23.
Lampard, Chelsea's record scorer with 211 goals in 648 appearances between 2001 and 2014, was named Everton boss in January 2022.
He was sacked eight days short of his one-year anniversary in that role.