The year-long deal begins with immediate effect and will see the companies share branding across the event and its various sessions, including the high-profile MacTaggart Lecture.
Freeview and YouTube will also work with festival organisers to advise on new trends within the industry, with a focus on distribution and targeting the youth demographic.
The new joint headline sponsorship replaces the previous relationship between BT and YouTube.
The Edinburgh TV Festival runs from 21-23 August. Confirmed speakers include director and Freaks And Geeks creator Paul Feig, who will deliver the Worldview Address.
Lisa Campbell, CEO and festival director, said: “We’re delighted to be able to welcome Freeview as headline sponsor alongside YouTube. Freeview is a perfect fit for the Festival given our shared desire to showcase the best British content, and both partnerships reflect the breadth of the TV industry and digital offering.”
Liz Reynolds, head of communications for Freeview, added: “Every year, the Edinburgh TV Festival reminds us why the UK is a leading creative force in a global TV market. We are thrilled to be involved. In a golden age of TV, Freeview brings together the best of British content both live and on-demand, and we’re looking forward to discussing how together we all ensure the UK remains centre stage going forward.”