The largest airlines in the world can be defined in several ways. ,

Delta Air Lines Delta Air Lines, Inc., typically referred to as Delta, is one of the major airlines of the United States and a legacy carrier. One of the world's oldest airlines in operation, Delta is headquartered in Atlanta, Georgia. The airline, along ...

is the largest by

revenue In accounting, revenue is the total amount of income generated by the sale of goods and services related to the primary operations of the business. Commercial revenue may also be referred to as sales or as turnover. Some companies receive rev ...

asset In financial accounting, an asset is any resource owned or controlled by a business or an economic entity. It is anything (tangible or intangible) that can be used to produce positive economic value. Assets represent value of ownership that c ...

s value and

market capitalization Market capitalization, sometimes referred to as market cap, is the total value of a publicly traded company's outstanding common shares owned by stockholders. Market capitalization is equal to the market price per common share multiplied by ...

, China Southern Air Holding by

passenger A passenger (also abbreviated as pax) is a person who travels in a vehicle, but does not bear any responsibility for the tasks required for that vehicle to arrive at its destination or otherwise operate the vehicle, and is not a steward. Th ...

s carried and revenue passenger mile,

American Airlines Group American Airlines Group Inc. is an American publicly traded airline holding company headquartered in Fort Worth, Texas. It was formed on December 9, 2013, by the merger of AMR Corporation, the parent company of American Airlines, and US Airways ...

by fleet size and number of

employee Employment is a relationship between two parties regulating the provision of paid labour services. Usually based on a contract, one party, the employer, which might be a corporation, a not-for-profit organization, a co-operative, or any ot ...

FedEx Express FedEx Express, a subsidiary of FedEx Corporation, is a major American cargo airline based in Memphis, Tennessee, United States. As of 2020, it is one of the world's largest airlines in terms of fleet size and freight tons flown. It is the na ...

by freight tonne-kilometers,

Ryanair Ryanair is an Irish ultra low-cost carrier founded in 1984. It is headquartered in Swords, Dublin, Ireland and has its primary operational bases at Dublin and London Stansted airports. It forms the largest part of the Ryanair Holdings famil ...

by number of routes,

Turkish Airlines Turkish Airlines ( Turkish: ''Türk Hava Yolları'') is the national flag carrier airline of Turkey. , it operates scheduled services to 340 destinations in Europe, Asia, Africa, and the Americas, making it the largest mainline carrier in the ...

by number of countries served and UPS Airlines by number of destinations served.

By company revenue

Note that

Emirates Emirates may refer to: * United Arab Emirates, a Middle Eastern country * Emirate, any territory ruled by an emir ** Gulf emirates, emirates located on the Persian Gulf ** Emirates of the United Arab Emirates, the individual emirates * The Emirat ...

is a state-owned company and is thus not included in this list of public companies. Its 2021 revenue was estimated over 18 billion USD, which would place the company into 5th place. Its 2014-2015 revenue was billion ( billion), profit billion ( billion), and assets billion ( billion), with 56,725 employees. Qatar Airways Group is similarly privately held.

By passengers carried

;Airline groups ;Airlines The

IATA The International Air Transport Association (IATA ) is a trade association of the world's airlines founded in 1945. IATA has been described as a cartel since, in addition to setting technical standards for airlines, IATA also organized tarif ...

reports numbers for individual air operator's certificates and groups of multiple airlines can report larger numbers. By passengers carried (thousands)