- Office de radiodiffusion télévision françaiseCountry: FranceFounded: 1964
- OkkoCountry: RussiaFounded: 2011
- OkooCountry: FranceFounded: December 9, 2019
- ORF 1Country: AustriaFounded: August 1, 1955
- ORTF Télévision 2Animated series: 2Format: television station
- OTVCountry: RussiaFounded: January 1, 1998
- OxygenCountry: United StatesFounded: February 1, 2000