Three flights were diverted to Stansted on Sunday night after a possible drone sighting at the airport but they were later able to return.
The flights – two from Barcelona and Amsterdam operated by easyJet and a British Airways flight from Heraklion – were sent to Stansted Airport.
Later the planes took off from Stansted and were able to land at Gatwick, more than 90 minutes after their scheduled arrival time.
A Gatwick spokesman said: "Gatwick investigated a report of an unconfirmed sighting of an object outside the airport’s 5km exclusion zone today but – following a full assessment – the airport has remained fully operational throughout."
Meanwhile, there was disruption on train services to and from Heathrow on Sunday due to a fire at an old coal depot in West Drayton, three miles away.
