About London
London is the capital and largest city of England and the United Kingdom, with a population of 9.1 million people in 2024. Its wider metropolitan area is the largest in Western Europe, with a population of 15.1 million. London stands on the River Thames in southeast England, at the head of a 50-mile (80 km) tidal estuary down to the North Sea, and has been a major settlement for nearly 2,000 years. Its ancient core and financial centre, the City of London, was founded by the Romans as Londinium and has retained its medieval boundaries. The City of Westminster, to the west of the City of London, has been the site of the national government and parliament for centuries. London grew rapidly in the 19th century, becoming the world's largest city at the time. Since the 19th century the name "London" has referred to the metropolis around the City of London, historically split among the counties of Middlesex, Essex, Surrey, Kent and Hertfordshire. Since 1965 it has largely comprised the administrative area of Greater London, governed by 33 local authorities and the Greater London Authority. Source: "London" by Wikipedia contributors (https://en.wikipedia.org/wiki/London), licensed under CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/). Edit history on the linked Wikipedia page.
Overview
London, United Kingdom is served by 5 airports tracked in this guide: London Heathrow Airport (LHR), London Gatwick Airport (LGW), London Stansted Airport (STN), London Luton Airport (LTN), London City Airport (LCY). Together they handle inbound and outbound flying for the metropolitan area, and each one links through to a full guide on this site with terminal, lounge, layover and ground-transport pages.
Choosing the right airport
Choosing between the airports in London usually comes down to three things: which airline you are flying, which route you need, and how you plan to reach the airport from town. The primary international gateway carries most long-haul flights and partner-alliance connections. The secondary fields are usually friendlier for short domestic hops and low-cost carrier routes. Always confirm which airport your specific flight uses before you book a transfer. A wrong-airport pickup can cost an hour or more in cross-town traffic, and a few low-cost carriers in United Kingdom are notorious for using the secondary field even on routes you would expect at the main airport.
Ground transport
Ground transport between central London and its airports normally includes licensed taxis with published rank fares, ride-hail apps with dedicated pickup points, public transport (bus, metro or rail) into the city centre, and rental car desks landside. For an early morning departure, a pre-booked airport transfer or an airport-hotel stay the night before is usually the most reliable option. Cash-only taxis still operate in parts of United Kingdom, so carrying a small amount of local currency is a sensible backup even if you plan to pay by card.
Layover tips
If you are visiting London, it often makes sense to combine the airport visit with a short stay nearby. Look at hotel clusters within a 15-minute drive of arrivals if you have an overnight layover, and check luggage storage options at the airport if you want to head into the city centre between flights. Most major airports now have a left-luggage office airside or landside, although prices and hours vary widely.
When to fly through London
When you fly through London matters more than you might think. The morning bank between roughly 6am and 9am is the busiest at most airports, with a second peak in the late afternoon as long-haul flights time their arrivals into evening connection banks elsewhere. If your dates are flexible, a midday departure usually means shorter security lines and a calmer terminal. The shoulder seasons either side of the local holidays tend to be the cheapest and the least crowded.