The Portugal midfielder has signed a five-year contract at Goodison Park after a successful loan spell last season.
Everton have signed Andre Gomes from Barcelona for a fee of €25 million (£22m/$28.4m)
The Portugal midfielder has signed a five-year deal at Goodison Park to become their second signing of the summer after Huddersfield Town goalkeeper Jonas Lossl joined on a free transfer.
Gomes spent last season on loan at the Toffees, making 29 appearances in all competitions.
“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 Everton’s website.
“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.”