According to GamesBeat, sources "familiar with the matter" have confirmed that Google's YouTube division – said to be leading proceedings – has completed the deal, two months after talks were reported.
The service lets users broadcast their own live gaming sessions from platforms including PC, Xbox One and PlayStation 4, with the site boasting more than 50 million monthly active users at present.
More than one million people upload content each month, with a number of content distribution partnerships also in place. Microsoft was another corporation reportedly interested in buying Twitch.
With YouTube also preparing a new music streaming subscription service, it will be interesting to see how its acquisition of Twitch strengthens the brand amid fierce competition from rival video services.