The Spaniard, who recently had a seven-month stint at Chelsea, has been unveiled as the new boss of the Partenopei by the club presidentNapoli president Aurelio De Laurentiis has confirmed Rafa Benitez as the club's new coach via Twitter.
The former Chelsea interim manager, who won the Europa League this season, is set to take over from Walter Mazzarri.
The 51-year-old recently left the Partenopei to join Inter after coach Andrea Stramaccioni was sacked for a disappointing ninth-placed finish this term.
De Laurentiis revealed through Twitter that he was delighted to land the 53-year-old.
He said: "Rafa Benitez is the new coach of Napoli. A man of great international experience. A leader."
The Spaniard has coached in Italy before, but endured an unsuccessful spell at Inter, lasting just six months after inheriting Jose Mourinho's treble-winning side.
The club released an official statement on their website saying: "Rafa Benitez is the new coach of Napoli. An agreement was signed [on Monday] in London.
"Napoli are happy to welcome a coach so prestigious to our own family. A welcome also to his collaborators."