Guus Hiddink has been appointed Chelsea manager until the end of the season, the Premier League champions announced on Saturday.
The experienced Dutch coach, 69, succeeds Jose Mourinho, who was sacked on Thursday, and returns to a role he previously performed in 2009, when he led Chelsea to glory in the FA Cup.
"I am excited to return to Stamford Bridge," Hiddink said in a statement on the Chelsea website.
"Chelsea is one of the biggest clubs in the world, but is not where it should be at the moment. However, I am sure we can all turn this season around.
"I am looking forward to working with the players and staff at this great club and especially renewing my wonderful relationship with the Chelsea fans."
Chelsea owner Roman Abramovich previously turned to Hiddink in February 2009 after sacking Luiz Felipe Scolari. Hiddink steered the club to a third-place finish in the league, the Champions League semi-finals and an FA Cup final win over Everton.
Abramovich has backed him to have a similar impact this time around.
"The owner and the board welcome back a coach with a wealth of top-level experience and success, including his previous spell with the club in 2009 when we lifted the FA Cup," Chelsea said in a statement.
"Mr Abramovich and the board believe that Guus has what it takes to get the best out of our talented squad."