As of early 2026, London Heathrow Airport (LHR) serves as a primary global hub for approximately 80 to 85 airlines. While this number fluctuates slightly due to seasonal schedules and airline mergers, it remains one of the most internationally connected airports in the world. As the primary hub for British Airways and a major base for Virgin Atlantic, it handles flights to over 200 destinations across 80+ countries. Every major global alliance—Oneworld, SkyTeam, and Star Alliance—has a significant presence here. Due to its "slot-constrained" nature, airlines often pay millions for the right to land at Heathrow, making it a highly competitive environment for carriers ranging from mega-airlines like Emirates and United to smaller national flag carriers. The diversity of airlines ensures that passengers can find direct or connecting flights to nearly every corner of the globe, supported by four active passenger terminals that are specialized by airline alliance and geographic region.