The Portuguese has signed a five-year contract and made permanent his switch from the Nou Camp after a successful season on loan at Goodison Park in 2018-19 and becomes the club's first major signing of the summer following the arrival on Jönas Lossl on a free transfer.
“I know the Club made a massive effort to sign me and I'm very happy and thankful to them,” Gomes told evertonfc.com. “I said during the year that I felt part of a family and that is the most important thing to me.
"Last year was a really good experience for me. I just wanted to feel part of something special and I found it here. It was good for me in that moment and right now, after signing for Everton, it's even better.
“I always got massive support since day one. I'm really happy to have this badge on me right now.
“I want to give all the fans my best because I think they deserve the best. I have to thank Marco and Marcel, too, because they made a really massive effort for me to be here.”
Gomes joined Barca in a big-money deal in 2016 that was worth €35m up front and included another €20m in appearance-related add-ons following his impressive form for Valencia and on the international stage for Portugal where he was in the team that won the 2016 European Championships.
He made just 29 starts in call competitions for the Liga giants, being used more as a substitute than a first-team regular as his much-vaunted move turned sour. Linked strongly with a move to Tottenham in the summer of 2017, Gomes would end up staying at Barca but was open about the psychological toll his poor form was taking and he welcomed the chance to join Everton on loan a year later.
A hamstring injury suffered during Barcelona's pre-season trip to the United States would prevent him from making his Blues debut until October but he quickly established himself as a vital member of Marco Silva's team and forming a strong partnership with Idrissa Gueye in central midfield.
The fee agreed with for his services will reportedly entail another £2m in add-ons that would take the final fee to around £24m should the Blues qualify for the Champions League during Gomes's time at Goodison.