Maurizio Sarri has said that he would give everything to win trophies with his new club.
Sarri managed Napoli last season and took them to within an inch of the Serie A title, eventually losing out to Juventus.
He replaces Antonio Conte, who was sacked after a season that saw Chelsea slip out of the top four in the Premier League.
Fans will be hoping Sarri can bring back attacking football to the club.
"I want to play my football," said Sarri in an interview with the Chelsea official app "The 5th Stand."
"I want to enjoy myself and probably to win something.
"The players have to enjoy themselves. First of all, I hope the fans can enjoy the team. I want to bring enjoyment to the fans, the fans have to be proud of the team.
"One hundred percent hard work and 90 percent fun."