Marko Arnautovic has completed his move from West Ham to Shanghai SIPG for an undisclosed fee, the Premier League club announced on Monday.
The Austrian scored 22 goals in 65 appearances in two seasons at the Hammers, but has been linked with a move to China since January.
"West Ham United can confirm that Marko Arnautovic has joined Chinese Super League champions Shanghai SIPG for an undisclosed fee," West Ham said in a statement.
Arnautovic will join forces with former Brazilian internationals Oscar and Hulk at the Chinese champions.
Shanghai SIPG are through to the 2019 AFC Champions League and will face Japan's Urawa Red Diamonds on August 27 and September 17.