Atlanta's airport is still the busiest passenger airport in the world.
More than 95 million passengers passed through Hartsfield-Jackson Atlanta International Airport in 2012, an increase of 3.3% over the previous year, according to Airports Council International's preliminary traffic results.
Beijing Capital International Airport came in second place, with more than 81 million passengers last year, an increase of 4.1%. London's Heathrow Airport came in third place with more than 70 million passengers, an increase of 0.9%, according to Airports Council International, the worldwide association of airports.
Tokyo International Airport (also known as Haneda Airport) handled more than 66 million passengers, a 6.7% increase in passenger traffic that was enough for fourth place. Chicago O'Hare International Airport, which handled more than 66 million passengers but saw a 0.1% decrease in traffic, landed in fifth place.
"Southwest is the largest airline in the country in terms of domestic passengers boarded and we're so proud to serve the world's busiest passenger airport," said Southwest Airlines spokesman Brad Hawkins, via email.
Worldwide passenger traffic increased 4% while cargo movements saw no increase over 2011.
Despite worldwide economic troubles, five airports in "emerging markets" with more than 40 million passengers in 2012 saw double-digit growth: Istanbul (20.6%), Dubai (13.2%), Jakarta (12.1%), Bangkok (10.6%) and Singapore (10%).
"As the global economy and international trade gradually picks up steam, we are optimistic to see stronger demand for air transport in the latter half of 2013," said Rafael Echevarne, Airports Council International director of economics, in a news release.
Rounding out the top 10 busiest passenger airports were Los Angeles, Paris, Dallas/Fort Worth, Jakarta and Dubai.