Largest airlines in the world
The largest airline in the world can be measured in several ways., United Airlines was the largest in terms of available seat miles, revenue seat miles, mainline fleet size, the number of both mainline employees and destinations served; Delta [Air Lines] was the most valuable by revenue, assets, market capitalization, and brand value; American Airlines Group carries the most passengers and has the most employees when American Eagle is included; FedEx Express carries the most freight in tonne-kilometers; Southwest Airlines has the greatest number of routes; and Turkish Airlines serves the most countries.
Financials
Note that Emirates is a state-owned company, and is thus not included in this list of public companies. Its 2024 revenue was estimated to be around $37.4B or 5th place. Qatar Airways Group is similarly privately held with its 2024 revenue of around $22.2B or 10th place.Brand value
| 2025 Rank | Airline | Country | $bn | Year-to-year change | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 1 | Delta Air Lines |  United Stateschange|14.9|10.771|disp=out|invert=on|dec=1|align=centerriseCapacityAirlines by available seat miles (ASMs)Numbers are listed in billions of available seat miles.
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Turkey