The winger has been rewarded for a fine first season at West Ham by being offered new terms until 2020.
Antonio joined the Hammers for a £7 million fee on a four-year contract from Nottingham Forest last summer after impressing in his first full season at the City Ground and starting last term in fine form.
The 26-year-old was not as illustrious a name as some of the other arrivals last summer, including France star Dimitri Payet, but he proved to be a huge hit in the final season at Upton Park.
Antonio hit eight goals in 26 Premier League appearances for the London club including five goals in eight games in a period of just over a month earlier this year.
Despite still having three years left on the initial deal he signed just 10 months ago he has been rewarded for his fine campaign with fresh terms, and he voiced his delight on his personal Twitter account on Monday.
Antonio tweeted: "Delighted to have signed my new contract! #COYI"
The former Sheffield Wednesday man will be hoping to play a similarly important role for the club this year in their first season at their new Olympic Stadium home, despite the Hammers having significantly strengthened their midfield this summer.
West Ham have already signed central midfielder Havard Nordtveit and Valencia winger Sofiane Feghouli in the transfer window, and the arrival of Feghouli will present Antonio with a big challenge to keep his spot next term.