Dubai International has taken over from Heathrow as the world's busiest international airport in terms of yearly passenger numbers.
The United Arab Emirates airport said it had just under 70.5 million passengers through in 2014, compared with around 68.1 million for Heathrow.
Dubai Airports said it had reached a "historic milestone".
Heathrow has been trying to increase capacity for a number of years, a spokeswoman said.
