Iwobi came through the ranks at the Gunners, scoring 15 goals in 149 games.

The Nigeria forward is Marco Silva's seventh summer signing.

"Alex was one of our main targets for this window and I believe he is a fantastic signing. He is a direct and skilful winger and attacking midfielder who always works very hard," the Everton manager said.

"He is still young but already with a lot of top-level experience - 100 Premier League matches, more in Europe and many international games.

"Alex fits exactly the profile of player I want. He is hungry to join Everton and take the next step in his career, to help us compete with the strongest teams in the league and reach his potential at our club."

Iwobi - whose arrival was announced more than four hours after the window closed - joins fellow new recruits goalkeeper Jonas Lossl, defender Djibril Sidibe, midfielders Andre Gomes, Fabian Delph and Jean-Philippe Gbamin, and striker Moise Kean.

Everton had an initial bid of £30m turned down but their improved offer - an initial £28m, rising to £34m with potential add-ons - was accepted.

Iwobi featured regularly last season under manager Unai Emery, appearing in all but three Premier League games, and he scored in the Europa League final defeat by Chelsea in what was his last appearance for the club.

There was increased competition for Iwobi's position at Arsenal following the arrival of Nicolas Pepe from Lille for a club record £72m.

Iwobi now begins a new chapter of his career at Everton, as the Toffees target an improvement on last season's eighth-place finish.

In an attempt to do that, Silva has reshaped his squad over the summer with seven arrivals and nine permanent departures.