A total of 16.8 million people used the airport during the first quarter, up 2.6%, helping to drive pre-tax profit to £23 million, an increase of 21.1%.
The airport secured another win over rival Gatwick when Garuda Indonesia started flying to the hub on March 31.
John Holland-Kaye, chief executive of Heathrow, said: "It’s been a fantastic start to 2016 and Heathrow is performing strongly on all fronts.
"At a time of uncertainty about Britain’s place in the world, families and businesses are counting on the prime minister to secure Britain’s long term future.
"An expanded Heathrow will be an economic powerhouse, a global symbol of a confident, outward looking Britain. Let’s make it happen."
