The world’s shortest international flight is Anguilla – St. Maarten flight which is only 12 miles. Anguilla is a British overseas territory in the West Indies in the Caribbean. Princess Juliana International Airport is located on the Dutch side of St. Maarten.
The route is operated three times daily by Anguilla Air Services (Q3) with Britten-Norman BN-2 Islander aircraft.
The next shortest international route used to be St. Gallen-Altenrhein, Switzerland and Friedrichshafen, Germany at 13 miles. However this route, which started in November 2016, was ended in April 2017.
Oddly CNN says the shortest international flight is the 50 mile Aruba to Punto Fijo, Venezuela route operated twice weekly by Aruba Airlines with a Bombardier CRJ. This is doubly strange because the article includes the 16 mile Kinshasa – Brazzaville and calls it the shortest flight between two national capitals (which makes it an international flight).
Kinshasa is the former Léopoldville, capital of what used to sometimes be referred to as The Conga as opposed to Congo-Brazzaville or just Congo. Democratic Republic of Congo used to be known as Zaire and was once Belgian Congo, Republic of Congo was once administered by the French.
The title for shortest regularly scheduled flight may belong to Logainair’s Westray – Papa Westray service. It’s scheduled at 2 minutes, but usually takes just 1 minute. It’s a subsidized route of less than 2 miles over water that began in 1967. These airports no longer appear to be listed on the Loganair website but the route still appears to be scheduled six times a week.
However Kegata – Apowo in Papua, Indonesia is slightly shorter. There appears to be video proof of the route online between 2013 and 2015. However I cannot find current service between these remote airports.