Traffic between Suvarnabhumi and Hong Kong airports ranks second highest on the list of the top five airports with the world's busiest air traffic, according to the International Air Transport Association (IATA).
The top five pairs of airports were all within the Asia-Pacific region, with Hong Kong and Taipei Taoyuan taking the top spot at 5.4 million people per year.
In second place, the traffic between Suvarnabhumi and Hong Kong reached 3.4 million last year, a 9% increase from 2017.
Experts attribute the growth to the surge in flights operated by low-cost carriers.
Also in the performance figures released by the IATA for 2018, airlines in the Asia-Pacific region once again carried the largest number of passengers worldwide.
In total, 4.4 billion passengers flew in 2018, with 22,000 pairs of cities connected by direct flights, up by 1,300 from 2017 and double the figure in 1998.
"Airlines are connecting more people and places than ever before. The freedom to fly is more accessible than ever. And our world is a more prosperous place as a result," said Alexandre de Juniac, IATA director-general and CEO.
The airlines with the highest number of total scheduled kilometres per passenger were American Airlines at 330.6 billion kilometres, Delta Airlines, United Airlines, Emirates and Southwest Airlines.
Meanwhile, the Star Alliance has maintained its position as the largest airline alliance in 2018, with 21.9% of total scheduled traffic worldwide, followed by SkyTeam and the Oneworld airline alliance.
