Flights from the west London airport resumed about an hour after police said a drone had been seen.
A Heathrow spokeswoman had said it was a “precautionary measure” to “prevent any threat to operational safety”. It comes after last month’s disruption at Gatwick Airport which saw thousands of people stranded when drones were sighted.
The spokeswoman said: “We continue to work closely with the Met Police to respond to reports of drones at Heathrow. Based on standard operating procedures, working with Air Traffic Control and the Met Police, we have resumed departures out of Heathrow following a short suspension. We continue to monitor this situation and apologise to any passengers that were affected by this disruption.”