Frank Lampard has vowed to 'give everything' to succeed at Chelsea and make supporters 'proud' of the club.
The 41-year-old, who took Derby County to the Championship play-off final in first season of management last term, has signed a three-year contract at Stamford Bridge where he spent 13 years as a player.
He takes over the reins from Maurizio Sarri who stepped down at Chelsea to become Juventus boss earlier this summer.
Sarri won the Europa League and steered the Blues to a third-place finish in the Premier League last season and Lampard is hoping to build on the Italian's work.
The legendary former midfielder insists he still has the hunger and drive to succeed after winning 13 trophies during his playing days in west London.
Asked what Chelsea fans can expect from his management, Lampard told Chelsea's official website: 'I'm delighted to be here. My smile probably tells them that anyway.
'The club has been in my heart for a long time and I have never forgotten that and never will.
'But once we've gone beyond that emotion - and I'm keen to go beyond that very quickly - I want to work.
'What they can expect is a manager that is going to give everything... every hour that I can in the day to work hard, to bring a team the fans can be proud of because this is a competitive club. It always has been in the modern era.
'I want to remain competitive, I want to try help with the younger players, try get them into squad because I know fans really relate to players who have come through the academy and fill the club.
'I'll work hard to try and bring success to the club.'
On Lampard's appointment, Chelsea director Marina Granovskaia said: 'It gives us great pleasure to welcome Frank back to Chelsea as head coach.
'Frank possesses fantastic knowledge and understanding of the club and last season, he demonstrated he is one of the most talented young coaches in the game.
'After 13 years with us as a player, where he became a club legend and our record goalscorer, we believe this is the perfect time for him to return and are delighted he has done so.
'We will do everything we can to ensure he has all the support required to be a huge success.'