The 25-year-old joined the Hammers from Championship side Nottingham Forest on transfer deadline day.
Antonio has arrived at the Boleyn Ground amid hype and expectation, and with a reputation that he was one of the best players in the Championship.
The Englishman has played for a number of clubs in his career, including Sheffield Wednesday and Southampton (on loan).
The former Reading man has stated that he wants to fulfil his contract with West Ham.
“I have a four-year contract here and I want to fulfil it,” Antonio told London24.com when asked if West Ham could finally be a long-term home.
Good signing for West Ham United
Antonio is a highly-rated winger who was one of the best players for Forest last season.
The former Wednesday player scored 14 goals and created 62 chances in 46 Championship games during the 2014-15 campaign.
The 25-year-old former Reading man had a pass accuracy of 60% and a shot accuracy of 44%, and won 151 headers, 104 dribbles and 42 tackles.
Antonio scored two goals and created nine chances in four Championship matches for the Reds this campaign before his move to West Ham.