The Spaniard's impending exit from Stamford Bridge had been known for some time and on Monday it was announced that he will become the new head coach of Serie A club Napoli.
Benitez took over at the Blues in an interim capacity in November following the sacking of Roberto Di Matteo and, despite enduring a torrid relationship with some of the fans in west London, he guided the club to third place in the Barclays Premier League and victory in the Europa League final.
His final act in charge was a recent tour of the United States, which ended in two defeats to Manchester City, and Chelsea have now confirmed the 53-year-old is free to join Napoli.
"Chelsea Football Club has today (Tuesday) released Rafael Benitez from his contract to become the new manager of Napoli," said a statement on the official Chelsea website.
"Rafa was appointed as the club's interim manager last November, and steered us to automatic Champions League qualification thanks to our third-place finish in the Barclays Premier League, while also leading us to the Europa League title in Amsterdam earlier this month.
"Also departing to join Napoli are first-team fitness coach Paco De Miguel and Xavi Valero, the first-team opposition analyst.
"Everybody at Chelsea Football Club would like to place on record our thanks to Rafa and his staff for their work at the club, and wish them success for the future."