The Nightingale Hospital in London is expected to be placed on standby in the coming days, and will no longer be admitting patients.
The hospital, which opened on 3 April with 4,000 beds to treat Covid-19 patients, could resume operations again if needed.
Fewer than 20 patients are being treated there at present, the BBC understands.
Staff will be redeployed, but some equipment will stay at the hospital.
In a briefing to staff, Charles Knight, CEO of the Nightingale London, said most of the hospital's capacity had not been used.
"Thanks to the determination and sacrifice of Londoners in following the expert advice to stay home and save lives, we have not had to expand the Nightingale's capacity beyond the first ward."
He added: "It is likely that in the coming days we will not need to be admitting patients to the London Nightingale, while coronavirus in the capital remains under control."
The hospital, which was formerly a large exhibition space in London's Docklands, was planned as part of the UK's response to the coronavirus pandemic.
Last week, it was revealed to have treated 51 patients in its first three weeks.
A spokesperson for the hospital previously said it would be a "mark of success" if the hospital did not operate at full capacity.
However Mr Knight said it would stand ready to be used again "as and when needed in the weeks and potentially months to come".
The Prime Minister said last week that the UK was "past the peak" in coronavirus cases.
Prof Stephen Powis, medical director of NHS England, indicated that the Nightingale hospitals would need to be kept as an "insurance policy for Covid patients".
The NHS is now moving into the second phase of its response to the global pandemic.
What's in the Nightingale in London?
The 87,328 square metres of double exhibition halls were fitted out with the framework for about 80 wards, each with 42 beds.
Some 500 fully-equipped beds, with oxygen and ventilators, were put in place with space for another 3,500.
If it did reach capacity, it would have been one of the largest hospitals in the world.