Larger aircraft carrying more passengers drove a 5.5% growth in passenger numbers using Heathrow last month.
The west London hub reported that it handled a record 5.27 million passengers in February over the same month last year.
This came as a more resilient UK economy saw travel demand pushed up higher than expected, the airport said.
Chief executive John Holland-Kaye said: “Heathrow is off to a flying start in 2017 – we’re delivering the best service of any major airport in Europe to record numbers of passengers and boosting British exports with record cargo volumes.
“Our new sustainability leadership strategy will make Heathrow a centre of excellence for sustainable aviation and planning for expansion is firmly underway with SMEs across Britain lining up to help us deliver it.”