Heathrow Airport is used by over 89 airlines flying to 214 destinations in 84 countries. The airport is the primary hub of British Airways and is a base for Virgin Atlantic. It has four passenger terminals (numbered 2 to 5) and a cargo terminal.

As of 2026, London Heathrow Airport (LHR) hosts over 80 different airlines, serving more than 230 destinations in nearly 90 countries. It serves as the primary global hub for British Airways and is a major base for Virgin Atlantic. The airport's four active terminals (Terminals 2, 3, 4, and 5) accommodate a vast array of international carriers, ranging from major legacy airlines like American Airlines, Emirates, and Lufthansa to smaller national carriers and long-haul specialists. Heathrow remains one of the busiest airports in the world by international passenger traffic, and its slot-constrained nature means that the airline list is relatively stable, though new entrants—particularly from growing markets in Asia and the Middle East—frequently apply for slots. The high volume of airlines ensures that Heathrow connects the UK to roughly two-thirds of the world's long-haul destinations, maintaining its status as Europe's most connected aviation gateway and a critical node in the global economy.