Financial details of the deal were not disclosed, but British media reported Everton had paid a fee of around £25 million to Napoli for the 29-year-old.

Allan scored 11 goals and grabbed 16 assists in more than 200 appearances for Napoli across all competitions, helping them claim the Coppa Italia last season.

“It is a real pleasure to sign for Everton. I am immensely happy to be here,” Allan said in a club statement.

“I hope, like I have done in my entire career, I contribute with my performances together with my teammates and that I put in some great games, great performances and win important things.”