Venture Beat reports that the service, featuring HBO movies and TV series, is being offered on a 30-day free trial basis on Apple’s little black box as well as through Optimum Online’s broadband service.
It is also being offered via mobile in both iPad and iPhone.
Following the trial, the cost of receiving HBO Now will be $14.99 a month.
Apple first announced a partnership with HBO for its streaming service last month during its Apple Watch press conference.
Prior to HBO Now’s launch, HBO offered streaming through HBO Go.
Reports say that Apple is likely to remain the exclusive provider of HBO Now on set-top boxes and mobile devices for only three months.