The 23-year-old has sealed a move to the Partenopei after weeks of speculation, but reiterated his desire to end his career back in Brazil with the Peixe.
The Partenopei had been heavily linked with a move for the 23-year-old in recent weeks, and the Brazilian giant confirmed a deal has been struck which will see the youngster join the Naples-based outfit on a five-year deal.
Serie A rival Roma had reportedly entered the race to sign the shotstopper, but, speaking to Santos' official website, Rafael confirmed the promise of Champions League football available at Stadio San Paolo heavily influenced his decision.
"I have the opportunity to play for one of the biggest clubs in the world, with one of the five best coaches in the world who has won the Champions League [Rafael Benitez]. All of this weighed heavily in my decision," Rafael said.
Rafael, who initially joined the Peixe as a 13-year-old, had previously expressed a desire to retire at the Vila Belmiro - a promise he intends to keep despite opting for a move to Europe.
"I've always had a desire to end my career here," Rafael said. "However, I have a dream of playing in the Champions League and becoming a champion of Europe, but I still wish to end my career at Santos."
The Brazil international conceded 208 times in 194 games, at an average of just 1.07 per game, in his three years as first choice goalkeeper.