Heathrow or Heath Row was a wayside hamlet along a minor country lane called Heathrow Road in the ancient parish of Harmondsworth, Middlesex, England, on the outskirts of what is now Greater London. Its buildings and all associated holdings were demolished, along with almost all of the often grouped locality of The Magpies in 1944 for the construction of Heathrow Airport.
The name Heathrow described its layout: a lane, on one side smallholdings and farms of fields and orchards which ran for a little over a one mile (1.6 km), on the other, until the 1819 Inclosure for farmland, common land: a mixture of pasture, hunting and foraging land on less fertile heath. Akin to Sipson Green it was a scattered agricultural locality of Harmondsworth. The two lightly populated places dotted the brickearth-over-gravel soils in the east of Harmondsworth which historically butted on to Hounslow Heath. Yards from the lane, while the heath existed, General William Roy mapped one end of the first baseline for measuring the distance between the Paris and Greenwich observatories, the first precise distance survey in Britain, in 1784.
By the late 19th century Heathrow had developed three main agricultural settlement clusters with orchards and fields worked by teams of labourers — Heathrow Hall, Perrotts Farm and on some measures Perry Oaks at a fork in the southwest end of the lane. Abutting The Magpies, east along the Bath Road, Sipson Green also lay in Harmondsworth, covered in the article on the hamlet-turned-village of Sipson. A small orchard founded before the 19th century Kings Arbour, Harmondsworth, separated The Magpies from Heathrow. The Magpies had a mission church of the parish and has kept one of its pre-1765 public houses, The Three Magpies.