Gatwick opened as an aerodrome in the late 1920s; it has been in use for commercial flights since 1933. The airport has two terminals, the North Terminal and the South Terminal, which cover areas of 98,000 m² (1,050,000 sq ft; 117,000 sq yd) and 160,000 m² (1,700,000 sq ft; 190,000 sq yd) respectively.

The South Terminal is the larger of the two terminals at London Gatwick (LGW) in terms of total floor area and historic capacity. Spanning approximately 160,000 square meters, the South Terminal is the original hub of the airport and handles a massive volume of short-haul and charter traffic, notably serving as the primary base for many of British Airways' European routes. The North Terminal, which opened in 1988, is slightly smaller at roughly 98,000 square meters, but it is often perceived as "more modern" and serves as the main hub for easyJet and several major long-haul carriers. Despite the difference in square footage, both terminals are highly efficient and are connected by a free, 24-hour automated people mover that takes only two minutes to travel between them. In 2026, both terminals have seen significant upgrades to security and retail, but the South Terminal's larger footprint allows it to house a broader range of dining options and larger departure lounges, making it the workhorse of the UK's second-busiest airport for both domestic and international connections.