London Heathrow (LHR) is one of the busiest global hubs, and in 2026, it is served by over 80 international airlines. British Airways is the largest operator, using Terminal 5 as its primary home. Virgin Atlantic is the second-largest, based in Terminal 3. Other major domestic and international carriers include American Airlines, Delta, United, and Air Canada (Terminal 2 & 3). Major Asian and Middle Eastern carriers such as Emirates, Qatar Airways, Singapore Airlines, Air India, and Japan Airlines also maintain high-frequency service. European flag carriers like Lufthansa, Air France, KLM, and Iberia provide dozens of daily short-haul connections. Recent additions in 2026 include increased service from newer carriers and low-cost subsidiaries like Eurowings. Whether you are flying to a regional UK city or a remote international destination, Heathrow's five terminals house a comprehensive array of the world's leading airline alliances.