All flights in and out were halted.
The runway has since reopened but passengers continue to face delays while airlines "catch up on the flight schedule", the airport said Thursday morning.
A police helicopter circulated the airport looking for the drones.
There were multiple reports of drone sightings since the initial report of two drones at 9.03pm local time on Wednesday (Thursday 5.03am, Singapore time), Gatwick said in an earlier statement.
Gatwick Airport, the second-busiest in Britain, said on Wednesday it had suspended flights while it investigated reports of two drones flying over its airfield.
Gatwick added that airlines had been working to provide delayed and diverted passenger with hotel accommodation or transport.
After spending about two hours on the plane, she said the couple were put on a bus to Gatwick, from where they had been due to fly to Istanbul.
While some were diverted to other London airports, others have reported being sent as far away as Paris, Bordeaux and Amsterdam.
"We apologise to any affected passengers for this inconvenience but the safety is our foremost priority".
In response to a customer query, British Airways said: "Gatwick have stopped all arrivals and departures due to a drone, we've been told".
"We will update when we have suitable reassurance that it is appropriate to reopen the runway". Flights were grounded and inbound planes were diverted elsewhere.
The second-busiest airport in the United Kingdom has had to divert flights to Stansted, Luton and Heathrow. Got a free can of Coke and Pringles.