Johnson’s message to the country, in which he introduced a three-week lockdown to help stymie the spread of COVID-19, was broadcast at 8.30 PM across BBC One, ITV, Channel 4, Channel 5, BBC News and Sky News.
In the 15-minute slot in which he was talking, nearly 28 million people were watching, according to live BARB ratings figures supplied by overnights.tv.
The staggering figure puts it ahead of many famous broadcasts in Britain, including the Opening and Closing Ceremony for the London 2012 Olympics, which were watched by 24.4 million and 24.6 million, respectively.
In fact, it may only be second to Princess Diana’s funeral, which was broadcast to an audience of 31 million in 1997.
Subscribe to Deadline Breaking News Alerts and keep your inbox happy.