Passengers will fly non-stop between New York and Singapore.
They will cover a distance of around 9,500 miles on the Singapore Airlines route.
New Airbus A35-900ULR aircraft will be used for the flights lasting up to 18 hours and 45 minutes.
They will be configured with 94 premium economy seats and 67 business class seats.
The existing longest passenger flight is operated by Qatar Airways between Doha and Auckland, at 9,025 miles.
Singapore Airlines served the Singapore-New York route until 2013 when it suspended flights due to high fuel costs.
The A35-900ULR offers better fuel efficiency and is designed to offer a more comfortable travelling environment with higher ceilings, larger windows, a wider body and lighting that reduces jetlag.
The UK’s longest non-stop route is the 9,009-mile Qantas service between London and Perth, which launched in March.