London Heathrow Airport (LHR) remains the most visited and busiest airport in the United Kingdom by a significant margin. In the most recent data for 2025 and early 2026, Heathrow handled over 80 million passengers annually. It serves as the primary gateway for long-haul international flights and is the home base for British Airways and Virgin Atlantic. Following Heathrow, the next busiest is London Gatwick (LGW), which is the world's busiest single-runway airport and serves as a major hub for low-cost carriers like easyJet and Norse Atlantic. Other major players include Manchester Airport (MAN), which is the busiest outside of London, and London Stansted (STN). However, none come close to the sheer volume of traffic moved by Heathrow. Despite ongoing debates about a "third runway," Heathrow's central role in global aviation ensures it stays at the top of the list for both passenger numbers and aircraft movements in the UK.