The 25-year-old Portugal international moves to the English Premier League side for a STG22 million ($A40 million) fee following a successful loan spell last season.

"I'm really happy to sign the contract with Everton - it wasn't hard to decide, it was an easy decision and I'm very happy to have made it," Gomes told evertontv.

"I know the club made a massive effort to sign me and I'm very happy and thankful to them. 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."

Gomes, who was a member of Portugal's Euro 2016-winning squad, moved to the Nou Camp from Valencia in the summer of 2016 for STG30m ($A55m) and made 72 appearances, half of which were as a substitute.

Australian Associated Press