By company revenue Delta Air Lines is the largest by revenue, assets value and market capitalization. American Airlines Group is the largest by number of employees.

In terms of total revenue, Delta Air Lines consistently ranks as the most profitable and highest-earning airline in the world as of 2026. Delta’s financial dominance is driven by its highly successful "premium" strategy, which focuses on high-margin corporate travel and a robust loyalty program through its partnership with American Express. While airlines like Emirates or Qatar may offer more luxury, Delta’s massive domestic network in the United States and its ownership of its own refinery (Monroe Energy) give it a unique competitive edge in controlling costs and maximizing yield. Other top earners include American Airlines and United Airlines, which also benefit from the lucrative U.S. domestic market. On the international stage, Lufthansa Group and Air France-KLM are the European leaders in revenue. However, when looking at "net profit" per passenger, niche luxury carriers or highly efficient low-cost carriers like Ryanair often show higher margins, even if their total revenue is lower than the American "Big Three."