The brand new NHS Nightingale hospital will care for 4000 coronavirus patients and is being built by up to 200 military personnel, including infantry from the First Battalion of The Royal Anglian Regiment.
Workers have been putting in long shifts to ensure the project is complete as quickly as possible as cases of coronavirus continue to rise day-by day.
There are currently 29,474 confirmed cases in the UK.
The death toll in 2,352.
The Queen is head of the Armed Forces, making it an especially proud moment for her Majesty.
The hospital will look after people affected by COVID-19 who are in need of intensive care.
The build is coming along fast, with expectations that the Nightingale will be able to admit patients by Friday.
It is part of the government's response to the coronavirus pandemic, which also includes a three-week lockdown and the closing of all non-essential businesses.
The new hospital will be housed in the ExCel convention centre and will help free up space in overcrowded London hospitals.
A tweet posted to the official Royal Family Twitter account on Wednesday afternoon shared a post from The Ministry of Defence.
The Queen shared a video showing members of the armed forces hard at work on the new hospital.
The monarch's message read: "Thank you to all those working hard to complete @NightingaleLDN Hospital, which will open this week to support patients with coronavirus."
The account's next tweet said: "As the Regiment's Colonel in Chief, The Duke of Gloucester has paid tribute to @RAnglians, who have been working alongside @NHSEnglandLDN and @defenceuk colleagues to complete the build."
The Duke of Gloucester is the Queen's cousin and Colonel in Chief of the Royal Anglian Regiment.
Another tweet quoted the Duke, who echoed the Queen's kind sentiments, saying: "In these challenging times, I am enormously proud of the Royal Anglian's role in helping to build @NightingaleLDN.
"It is a testament to the @RAnglians's dedication, teamwork and professionalism.
"Their commitment will make a huge difference to lives up and down the country."
Meanwhile, Kate the Duchess of Cambridge, and Prince William, have shown their support for Prince Charles in a heartwarming message after he was cleared from coronavirus.
William and Kate praised the 71-year-old after he addressed the nation on Wednesday.
This was the first time that Charles had been seen since his battle with coronavirus.
During his speech, Charles thanked the NHS workers and volunteers and neighbours who are providing care for the vulnerable in their time of need.
The footage was taken from the Prince of Wales' home office at his Scottish residence, Birkhall, where he is currently self-isolating.
The video was shared on the Clarence House Instagram account.
The Duke and Duchess of Cambridge also re-posted the footage on their own social media page, Kensington Royal.
They shared the clip alongside the message: "A message from The Prince of Wales," and a star emoji reading "tap to watch".