Heathrow’s passenger numbers fell by 97% in April compared with the same month in 2019.
The airport announced that it was used by just 206,000 travellers last month, which is “the same number it would typically serve in just one day”.
The coronavirus pandemic has led to a collapse in demand for flights.
Many of the passengers who did travel through Heathrow last month were on board the 218 chartered repatriation flights that landed at the west London airport.
Heathrow is expecting demand to “remain weak” until countries lift their coronavirus lockdowns.
The impact of Covid-19 on global trade is highlighted by the amount of cargo passing through Heathrow last month falling by 62% to 51,000 metric tonnes.
This is despite the number of cargo-only flights being up to 14 times per day higher than normal.
Most cargo is normally carried in the belly hold of passenger jets, which have mostly been grounded.
Heathrow chief executive John Holland-Kaye said: “Aviation is the lifeblood of this country’s economy, and, until we get Britain flying again, UK business will be stuck in third gear.
“The Government needs to urgently lay out a road map for how they will reopen borders once the disease has been beaten, and to take an immediate lead in agreeing a common international standard for health in aviation that will allow passengers who don’t have the infection to travel freely.”