Everton secured Allan’s signing from Serie A club Napoli.
On Saturday the club announced the arrival of Allan, who struggled under Genarro Gattuso at Napoli for game time.
Carlo Ancelotti continues to rebuild his Everton squad.
With the Italian keen to be reunited with his former player, Allan was thought to be a key signing in this window for Ancelotti.
With Allan, a combative midfielder capped by Brazil nine times, Ancelotti has now got his wish to join Everton on a three-year deal for a reported fee of £22.2million (€25 m) plus add-ons.
“It is a real pleasure to sign for Everton. I am immensely happy to be here,” Allan told evertontv. “I hope like I have done in my entire career, I contribute with my performances together with my team-mates and that I put in some great games, great performances, and win important things.”
“It is a club with a rich history in the Premier League, has real ambition, and then there is Professor Ancelotti.”
“He has done everything possible to bring me here.”
“It is the size of the club and the name of the coach which means you don’t think twice about coming to Everton.”