The 34-year-old Brazilian announced in March he would be leaving the Bernabeu at the end of the Primera Liga season, and he has now accepted a new challenge with Fenerbahce, where his countryman Zico is the coach.
"I will play in Turkey at Fenerbahce," confirmed Roberto Carlos.
"They are the club who were most interested in signing me and I have been convinced of the plans which they want to develop.
"They have spoken with me a lot and what has been very important for me to take this decision is that Zico is their coach.
"I had other offers from teams in Italy, England and other countries, but Fenerbahce want to grow as a club and I want to help them."
Roberto Carlos has spent more than a decade at Real Madrid since joining them from Italian side Internazionale in 1996.
During that time he has won three league titles and three Champions League crowns with Madrid, while there could yet be more silverware on the way.
Madrid are currently top of the Primera Liga standings and know if they win their final two games they will be crowned Spanish champions for the first time since 2003.
Roberto Carlos has played a large part in Madrid's success over the years, but the flying full-back admits it is now time to move on and leave the Spanish side to continue their rebuilding.
"I think that I am in good form and as I already said I want to leave the way open for Real Madrid so they can begin a new cycle and let other players come in."
The former World Cup winner insists he is not turning his back on Spain altogether though, hinting he may return one day as a coach.
"I thank Spain and Real Madrid. I will return to Spain because I feel connected to this country," he said in Marca. "In the future I want to coach and who knows if it will be at a Spanish team."
Fener vice-president Murat Ozaydinli was understandably delighted with the acquisition.
He said: "We have transferred a player that conforms to the traditions of Fenerbahce.
"How great it is that today we don't have too much difficulty in signing players of legendary status."
The player's agent, Dino Pasalic, claimed his client had wanted to secure the move last season but first had to see out his contract in the Spanish capital.
"He made a promise to Fenerbahce last year and Carlos always keeps his promises," said Pasalic.