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.”