The world’s closest airports are just over one mile apart from each other - but are in different countries.

Brown Field Municipal Airport in San Diego, California and Tijuana International Airport are separated by little more than a college campus, an industrial estate - and one of the world's most famous international borders.

Located 13 miles southeast of downtown San Diego, Brown Field Municipal Airport is mainly used for private, corporate, and flight training activities. 

It is around 20 miles from San Diego International Airport - which is the third busiest airport in California in terms of passenger traffic.  

However, Brown Field is just over one mile away from Tijuana International Airport - which is so close to the US/Mexico border that it has a Cross Border Xpress (CBX) terminal in the United States. This rare feature allows passengers in the US with a boarding pass to walk across a bridge crossing the border.  

Tijuana's CBX terminal handled more 4,288,000 passengers in 2023 - approximately one-third of all passenger movements at the airport. It is the fifth busiest airport in Mexico for both passenger numbers and aircraft movements.

When it comes to international airports, Tijuana and San Diego are just 29 miles apart. This makes them two of the closest international airports to each other - but they're not the closest.

Some say this honour belongs to  William P. Hobby Airport and George Bush Intercontinental Airport in Houston, Texas.  These two airports are part of the same metropolitan area - and are just 23 miles apart.

However, it seems that Houston's claim does have a problem... as some people argue that the two closest international airports are  New York's LaGuardia Airport (LGA) and John F. Kennedy International Airport.

While these airports are just 10 miles apart, LGA is mainly used for domestic flights these days. Consequently, some people argue LGA is not a true international airport.   

Others say that San Francisco and Oakland are the closest international airports, as they are just 11 miles apart, as the crow flies.

But the distance by road is about 30 miles - which perhaps strengthens Houston's claim to being home to the World's two closest international airports.

Another notable mention are two international airports that share a runway that straddles the US/Canada border. 

However, Del Bonita and Whetstone International Airports share the same facilities - and so it is essentially one airport with two names.