The airport claims that the Royal Wedding "led to a surge in passengers in May" as wedding watchers from the US travelling to nearby Windsor pushed up passenger numbers 5% on North American flights.
Domestic flights also saw an uplift, boosted 5.5% as more passengers filled flights to Aberdeen, Edinburgh and Leeds.
While over 144,000 metric tonnes of cargo passed through Heathrow in May, the 22ndconsecutive month of record growth at the UK’s largest port by value for non-EU trade.
Long-haul markets were the fastest growing markets for cargo, with Japan (28%) and Brazil (33%) taking the top spots.
The UK's hub gateway also notes that in May Heathrow welcomed the arrival of new direct services to the cities of Wuhan and Sanya, operated by China Southern.
The airport’s connection to Sanya is a first for Europe.
And, according to Heathrow, rhe routes will allow for 6,000 metric tonnes of additional cargo capacity and over 110,000 new seats for passengers annually.
Talking about the impending Parliamentary vote on expanding Heathrow, airport CEO, John Holland-Kaye said: “We have a robust plan to expand Britain’s hub airport, unlocking billions in growth and creating tens of thousands of new skilled jobs – from Plymouth to Perth and Swansea to Southend.
"With strong cross-party support and a united voice from business and unions – MPs must finally seize the opportunity to expand Heathrow and secure a prosperous future for all of Britain.”