Kean moves for an undisclosed fee, reported to be an initial 32 million euros ($A52.2 million), after scoring eight goals in 21 appearances for the Italian champions.

"I was convinced to sign because Everton is a club looking to the future and so am I," the 19-year-old told EvertonTV.

"I know about the size of the club. It has big ambition and I will work very hard to help us fulfil what we want to achieve."

Kean has also scored twice in three games for Italy since making his international debut in December of last year.

"He is strong, fast, with many good qualities as a striker and he is just 19 years old," manager Marco Silva said of Kean.

"He has talent and he is ready to work, ready to improve our squad and gives us different solutions."

Everton open their Premier League campaign at Crystal Palace on Saturday.

Australian Associated Press