Aviation Atlanta the world's busiest airport in 2015 By Robert Silk / February 17, 2016 Share 1 -- Four U.S airports were among the 10 busiest in the world last year, according to a compilation of preliminary traffic results assembled by Airport World. Topping the list was Hartsfield-Jackson International Airport in Atlanta, which, with a passenger count of 101.5 million, became the first airport to service more than 100 million flyers in a year. Chicago O’Hare, with 76.9 million passengers, was the world’s fourth-busiest airport in 2015, leaping from seventh spot a year earlier on the strength of 9.8% growth. Los Angeles International Airport served as a gateway to 74.9 million flyers, good for seventh on the list. And Dallas/Fort Worth was the world’s tenth-busiest airport last year, serving 64.1 million travelers.Leading the way among foreign airports was Beijing Capital, which welcomed 89.9 million passengers, second most in the world. Dubai, with 78 million flyers, jumped from sixth to third on the strength of 10.7% growth.Rounding out the top 10 were Tokyo Haneda in fifth, London Heathrow (Europe’s busiest airport) in sixth, Hong Kong in eighth and Paris Charles de Gaulle in ninth.