Arnautović began his career in his native Austria playing in the youth teams for a number of clubs in the Vienna area before he signed a contract with Dutch club Twente in 2006. He impressed at De Grolsch Veste and after a fine 2008–09 season he joined Italian giants Inter Milan on loan, where he made only three appearances due to injury. He joined German side Werder Bremen in June 2010 and became a regular member of the first team. In September 2013, Arnautović joined English side Stoke City, where he scored 26 goals in 145 appearances. He joined West Ham United in July 2017 for a fee of £20 million, and two years later Shanghai SIPG (now Shanghai Port) for £22.4 million.