The Brazilian goalkeeper spent two years with the Italian champions but was limited to just 11 Serie A appearances in that time due to the presence of Gianluigi Buffon at the club.
Neto has now put pen to paper on a deal which will keep him at the Mestalla until 2021, with his buyout clause being set at €80m (£70.7m).
"I would to thank everybody who has helped me to be able to come here to Valencia CF, which is a club that I really want to be a part of and do my bit for. As soon as I knew I had the chance to come here and I knew that Valencia CF were interested in me, I did everything I could to be a part of this project," he told the club's official website.
"For sure it's the best for my career, for this moment in my career, to be part of such a historic and important club as Valencia CF. I know the history of this club and I know about the important players who have played here, I really want to do my bit to add to that history.
"I think I'm a fast goalkeeper and I'm technically sound, but I'm going to let the fans decide what they think of me. The main thing is that I'm really up for doing everything possible to take Valencia CF back where the club belong.
"The gaffer, along with the directors, and the club itself, Valencia CF, has been fundamental in the fact that I wanted to come here and give everything I've got for the fans and for this club. Having the responsibility of knowing that a coach like Marcelino is here at a Valencia CF, was crucial for me."
Neto joins a side which finished 12th in the La Liga table last season.