InterGlobe Aviation Limited, doing business as IndiGo, is a low-cost airline headquartered in Gurgaon, Haryana, India. It is the largest airline in India by passengers carried and fleet size, with a 60.5% domestic market share as of March 2024. It is the largest individual Asian airline, and one of the largest in the world in terms of passengers carried, with more than 100 million passengers carried in 2023. As of May 2024, IndiGo operates over 2,000 daily flights to 122 destinations – 88 domestic and 34 international, with a fleet of over 350 aircraft. It has its primary hub at Indira Gandhi International Airport, Delhi.

The largest airlines in the world can be defined in several ways. As of 2023, Delta Air Lines is the largest by revenue, assets value, fleet size, and market capitalization; American Airlines Group by passengers carried, revenue passenger mile, number of employees and destinations served; FedEx Express by freight tonne-kilometers; Ryanair by number of routes; and Turkish Airlines by number of countries served.