The Hammers will pay £5million for the loan, and t he 25-year-old's move will become permanent - for a further £20million fee - if he makes a set number of Premier League appearances for the club this season
Zaza becomes West Ham's 11th signing of a busy summer
Zaza, who scored at London Stadium while playing for Juventus in pre-season, said on the club's official website: "I want to thank everyone for welcoming me including the fans and everyone at the club
I wanted to start a new experience and I feel this is the right choice for me.
"I have been fortunate enough to have already played at the new stadium with a different shirt
It is a beautiful stadium and I felt the warmth of the fans and this was a big reason why I wanted to join the club.
"I want to become a better player and I know I can do that at West Ham
Unfortunately we could not qualify for the Europa League, but I am hoping I can help the club do that next season."
Zaza joined Juve from Sassuolo last summer and helped the club win the Serie A title and Coppa Italia, scoring eight goals in 24 appearances in all competitions.
Capped 14 times by his country, Zaza played for Italy at Euro 2016 although his tournament is best remembered for a terrible penalty miss in a shoot-out he had come off the bench specifically to take part in as the Azzurri lost to Germany in the quarter-finals
West Ham have already signed the likes of Andre Ayew, Manuel Lanzini and Sofiane Feghouli this summer, and said on their website that the deal for Zaza takes their spending past the £60million mark.
" The signing again illustrates the board's commitment to reinvesting the revenue raised from the club's move to London Stadium and building a squad commensurate with those stunning surroundings," the statement said
Source : PA
Source: PA