— FC Nantes (@FCNantes) September 1, 2015
The 26-year-old defender joined the French club in 2009, and went on to become one of the best central defenders in the league.
He has played 171 league matches and has scored nine goals for Nantes.
Chelsea have made a stuttering start to the 2015-16 Premier League campaign, having suffered two defeats already in their opening four matches.
Jose Mourinho was keen to sign a central defender, with John Terry and Branislav Ivanovic both having fared miserably so far.
Chelsea were reportedly interested in signing John Stones, and the Blues have had three bids rejected for the Everton defender. The Merseyside club were reluctant to sell their prized asset, as a result, the Blues had to look for options elsewhere.
French newspaper L’Equipe claimed today that the decision to sign Djilobodji has come from Chelsea’s scouting department rather than Mourinho, so he will have to prove himself to the Chelsea boss in order to get regular game time.
Djilobodji becomes the ninth signing of the summer for Chelsea, with the Premier League champions having added Pedro, Rahman Baba, Begovic, Kenedy, Nathan, Manea, Pantic (free), and Falcao, already to their star studded squad.