Northolt Aerodrome is an airfield in west London in the London Borough of Hillingdon (IATA Airport Code: NHT). It is located roughly 10km north of London Heathrow Airport. It was an active RAF base during World War II, became a significant civilian airport soon afterwards and reverted to military use upon the opening of Heathrow. Today it is an important RAF airfield, although since about 1980 privately owned aircraft, mainly corporate jets, have outnumbered military flights.

Two pilots of Boeing 707 jetliners mistakenly flew approaches to Northolt's shorter runway after they had been cleared to land at Heathrow. Luckily no casualties resulted from either the mistaken landing or the low "go-around". The body of Diana, Princess of Wales was flown to Northolt from Paris prior to burial at Althorp. A memorial to Polish airmen who died during the Battle of Britain stands next to the south eastern corner of the aerodrome.

After some 30 years of protracted consideration an Instrument Landing System was fitted to runway 25 and aggregate-filled safety pits were installed at either end of that runway.