Opinion

January 12, 2026 — 5:00am

Aviation data specialist OAG has released its annual analysis of the world’s busiest flight routes, and sitting in sixth place is the Melbourne-Sydney route which saw close to 9 million scheduled seats in 2025. Front-runner among the city pairs is Jeju International–Seoul Gimpo in South Korea, which has been rusted onto the top rung for more than a decade. In 2025 that route – just 243 nautical miles (450 kilometres) – had 14.4 million airline seats.

Note that this is a measure of airline capacity, determined by the number of airline seats available on flights between those cities. While it does not indicate the total number of passengers carried, the OAG survey is widely accepted as the definitive measure of what the title suggests – the world’s busiest air routes.

Without breaking the Qantas Group and Virgin Australia duopoly, airfares on Australia’s busiest route are unlikely to fall.iStock

The number of flights on our busiest domestic route is mind-boggling. On January 7, 2026, Qantas and Jetstar operated 51 flights from Sydney to Melbourne. On that same day Virgin Australia operated 21 flights on the route.

As well as popular, the Melbourne-Sydney route is incredibly lucrative. In a Visual Capitalist article published in April 2024, the world’s busiest flight routes were ranked by revenue. In the first half of 2023, the most lucrative route was between Sydney and Melbourne, which generated a total ticket revenue of $US1.21 billion ($1.8 billion). The article went on to note “this route is earning more than twice that of pre-pandemic levels, even as the number of passengers declined.”

The price of air travel between Sydney and Melbourne has been relatively stable in the post-COVID period. According to figures from Australia’s Bureau of Infrastructure and Transport Research Economics (BITRE), the average real price of a discount one-way economy airfare between Melbourne and Sydney in 2025 was $192, which is about the same as the previous year.

However, that flies against the general cost of domestic air travel, which moved lower during 2025. Figures from BITRE confirmed that domestic economy airfares were lower in 2025 than at any other year in the previous five-year period, especially early in the year. Domestic economy airfares were 12 per cent cheaper in the first two months of 2025 than in the same months in 2024, according to data compiled by corporate travel adviser FCM Consulting.

Western Sydney International Airport could be an “X factor” when it opens later this year.Bloomberg

The reason for the drop was a reduction in the world price of aviation fuel. Fuel cost is a major component in air ticket prices, and in 2025 the world price of jet fuel fell by close to 17 per cent compared to the previous year. But in the case of Sydney-Melbourne airfares, high-demand offset the cost savings created by lower fuel prices, particularly in the final quarter of 2025.