Which is the biggest airport in the world?

King Fahd International Airport, Damman, Saudi Arabia. 780 square kms. wow… you learn something everyday.

If the metric is passengers it seems Atlanta wins.

http://en.wikipedia.org/wiki/World's_busiest_airports_by_passenger_traffic

I guess it depends on if you mean size or traffic or even air traffic for that matter.

It depends on the criteria which you use to measure this, but in terms of passengers handled I believe it is Atlanta, and I expect that would rank top for emplanements, too. In terms of size, the previous poster is correct and the Saudi Arabia one has a larger surface area, I believe.

Beijing Airport is the biggest airport in the world.