The former Manchester City goalkeeper made the move on Tuesday.
Ederson said, "I have to say I'm very, very happy. It will be a new and important challenge for me, and I'm convinced we'll experience wonderful moments, both for the club and for myself.
"I want to enjoy every moment of my time here, and the goal is clear: to win trophies and contribute as much as possible to the team."
Ederson was pursued by Fener's bitter rivals Galatasaray for much of the summer and he also said, "The negotiations were incredible, both for the discussions we had and for the quality of the project presented to me. It was all very convincing.
"This team has top-notch players, as well as friends I've known for a long time. I can't wait to reunite with them and fight together on the pitch. By working hard together, we will take the club to the top."
Finally, a message to the fans: "I ask our supporters to always stand by us. I believe that with their support we will have a great season. My teammates and I will give everything we have to repay their support in the best way possible, leading the club to win titles."