The cachet of being known as the world's busiest airport is fiercely fought over by owners of the world's largest airports.
The following airports have variously made claims (or had claims made for them).
- O'Hare International Airport, Chicago, Illinois, USA - Largest number of passengers annually (pre-1998, 2003-date) - Most arrivals and departures annually (pre-1998, 2001-)
- Hartsfield-Jackson Atlanta International Airport, Atlanta, Georgia, USA - Largest number of passengers annually (1998-2003) - Most arrivals and departures annually (1999-2000)
- Heathrow Airport, London, UK - Largest number of international passengers annually
- Frankfurt International Airport, Frankfurt, Germany - Most international destinations served.
- Memphis International Airport, Memphis, USA (home of FedEx) - Most cargo traffic by volume annually
- Hartsfield-Jackson Atlanta International Airport, Atlanta, Georgia, USA (ATL) 58,875,694
- O'Hare International Airport, Chicago, Illinois, USA (ORD) 51,831,684
- London Heathrow Airport, London, United Kingdom (LHR) 47,503,540
- Tokyo International Airport, Tokyo, Japan (HND) 47,319,962
- Los Angeles International Airport, Los Angeles, California USA, (LAX) 41,289,216
- Dallas-Fort Worth International Airport, Dallas/Fort Worth, Texas, (DFW) 39,389,348
- Frankfurt International Airport, Frankfurt, Germany (FRA) 36,487,978
- Charles De Gaulle International Airport, Paris, France (CDG) 36,349,565
- Schipol Airport, Amsterdam, The Netherlands (AMS) 30,350,231
- Sky Harbor International Airport, Phoenix, Arizona (PHX) 28,152,396