The vaccinations were administered by a primary care physician at Windsor Castle, a royal source said.
To avoid inaccuracies and further speculation, Her Majesty, 94, decided she would let it be known that she had the vaccination, the source added. Her husband is 99 years old.
According to figures from Johns Hopkins University on Saturday, the UK has recorded more than 3 million cases of Covid-19 and more than 80,000 deaths.
The UK reported 1,325 fatalities related to the coronavirus on Friday – the highest daily increase in deaths ever.
In the capital, the mayor of London on Friday declared a “major incident”, warning that the city’s hospitals were on the verge of being overrun.
“The situation in London is now critical as the spread of the virus is spiraling out of control,” Mayor Sadiq Khan said in a statement.
“The number of cases in London has risen rapidly with over a third more patients now being treated in our hospitals compared to the peak of the pandemic last April.
“We are reporting a major incident because the threat this virus poses to our city is at a crisis point,” Khan added. “If we don’t take immediate action now, our [National Health Service] can be overwhelmed and more people will die. “
CNN’s Zamira Rahim and Amy Woodyatt contributed to the reporting.