The free-to-access channel will host gig highlights, band interviews and backstage features to a wider audience.
O2 sponsors venues in London, Glasgow and Manchester, among other cities.
Marketing activity to support the launch includes search and video ads through Google and YouTube, and a dedicated Facebook page.
O2 is also encouraging fans to record and upload content from concerts, and will host new films made from the films taken by fans at gigs, to create new content that is overlaid with high-quality audio from the concert.
Jasmine Skee, head of music sponsorship for O2, said the channel was a massive area of growth, and would bring music fans close to the O2 brand.
She said: "This is on the back of a five-year deal with Academy's venues to create up to 15 O2-branded venues."
Skee said the concept was to engage with gig-goers online before, during and after the event, but also to extend the experience to those at home, including streamed performances.
O2 has already filmed backstage interviews with Jason Derulo, Thin Lizzy, KT Tunstall, Europe, and Example, and further content will include video diaries.
Venues will also have "shoutout booths" installed, which fans can use to record messages to artists and give feedback on gigs.
Skee said: "O2 Academy TV celebrates the raw aspect of live music in our venues, giving fans a unique opportunity to get closer to the artists they love, and giving artists a creative platform to promote their shows."
O2 revamped its ad strategy earlier this year to feature a Narnia-inspired fantasy world, with the strapline "We are always thinking about you".