Di Matteo, 42, was promoted from assistant manager into temporary charge of the Blues in March following a poor spell under then-boss Andre Villas-Boas. He then led Chelsea to their fourth FA Cup success in six seasons before masterminding their maiden Champions League title with victory over Bayern Munich on penalties.
The former Italy midfielder, who also enjoyed a distinguished playing career at Stamford Bridge, has now been given the job full-time after signing a two-year deal and is looking to build on those successes. He said: "I'm obviously delighted to have been appointed as manager and first-team coach."
He added: "We all achieved incredible success last season that made history for this great club. Our aim is to continue building on that and I'm already planning and looking forward to the squad's return for pre-season."
It was widely expected that Di Matteo would be given a more permanent deal following his successful temporary tenure but there were reports Chelsea owner Roman Abramovich was looking at other targets, with former Barcelona boss Pep Guardiola high on his wanted list.
Di Matteo's deal was delayed as the club had to wait for him to return from his holiday before finalising the deal with the Italian becoming Chelsea's eighth permanent boss since Abramovich purchased the Stamford Bridge outfit in 2003.
Despite collecting honours in cup competitions Di Matteo could only guide Chelsea to a sixth-placed finish in the Barclay's Premier League but the club's chief executive Ron Gourlay is delighted to secure the long-term services of the ex-West Brom manager.
"Although he has set the bar very high in the short time he has been in charge, we know that Roberto is the right man to lead Chelsea onto further success," he said.
"We all believed he was a young coach with much to offer when we first asked him to take charge of team affairs in March and the manner in which he worked with us, the players and all the staff, and the success that followed, made him the clear choice when it came to selecting the person to take us forward in the seasons to come."
Source: PA
Source: PA