List of the busiest airports

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

A 'passenger' is typically described as someone who arrives in, departs from or transfers through the airport on a given day.