RT reached 2.5 million UK viewers in the third quarter of 2012, according to BARB data, making it the third-most watched rolling news channel in Britain, behind BBC News and Sky News.
In December 2012, the broadcaster switched its main production operation to a new state-of-the-art HD facility in Moscow.
Sky, which has carried the RT channel in the UK and Ireland since 2006, this month started offering the resulting RT HD service.
Margarita Simonyan, RT's editor in chief, said that the switch to HD has been "an important step for our network".
"We're very happy that thanks to BSkyB our UK audience can now enjoy the best RT programming in HD so soon after we completed the switch," she said.
RT is a 24/7 news channel which brings "the Russian view on global news". The global network broadcasts in English, Arabic and Spanish from its studios in Moscow and Washington, DC.
It is available to 550 million viewers worldwide, and is the only Russian TV channel to gain two Emmy International Award nominations.
RT is available at channel 518 on Sky, and the new HD network can be watched at 512 on the TV guide.