The upturn at Heathrow, which represented the airport's ninth consecutive year of growth, was driven by larger and fuller aircraft.
The UK gateway also handled 1.6 million tons of cargo during 2019.
Heathrow CEO John Holland-Kaye said: “The past decade has been transformational for Heathrow and the investments that we’ve made in our infrastructure, our people and our processes are paying off for passengers.
"But it doesn’t end there. By the end of this new decade of delivery, a third runway will have given Britain more hub capacity than our rivals in France or Germany, making this country a winner and the best-connected country in the world.
"Regular, direct flights to all the major cities in the US, India and China – the great economies of the 21st Century – will put all of Britain at the heart of global trade and we look forward to delivering this economic growth in a way that aligns with the Committee on Climate Change’s net zero 2050 target.”
Munich Airport attributed its 2019 rise in passenger numbers to its expanding route network, which led to a 1% increase in air traffic movements.
The German gateway notes that it enjoyed a 9% year-on-year rise in passengers in the intercontinental sector, a 4% increase in European traffic and a 1% upturn in domestic travellers, all of which "Munich Airport's growing strength as a hub".