Maurizio Sarri will replace Antonio Conte, who was sacked on Friday.
Chelsea are already a week into their pre-season training, but Sarri is eager to get started in his new post.
“I look forward to starting work and meeting the players on Monday ahead of travelling to Australia, where I will be able to get to know the squad and begin our match action,” he told the club’s official website.
“I hope we can provide some entertaining football for our fans, and that we will be competing for trophies at the end of the season, which is what this club deserves.”
Director Marina Granovskaia stated: “We are delighted to welcome Maurizio and are looking forward to him bringing his football philosophy to Chelsea.
“Maurizio’s Napoli side played some of the most exciting football in Europe, impressing with their attacking approach and dynamism, and his coaching methods significantly improved the players at his disposal.
“He has plenty of experience in Serie A and the Champions League and we know he is relishing the chance to work in the Premier League.”