Farms and other small settlements in Mill Hill date to at least the 10th century and are included in Domesday Book as part of the description for Hendon. Mill Hill only became an independent parish with its own church in 1836, measuring 3,570 acres including The Hale. There is no mention of a mill at this time. Until the 16th century the area of Mill Hill was known variously as Lothersleage, Lothersley and latterly Lotharlie.
The first reference to a mill in the area was in the 1350s. Melnehel (1374), may be a very early use of the name, but seems to have fallen out of use. The oldest documented use of the modern name Mill Hill (Myll Hylles) is much later (1544) and describes a mill which was until the mid-18th century on Holcome Hill. The writer Ralph Calder points out that the names of prominent local families found in a medieval survey of Hendon and Mill Hill (the Black Book of 1321) are familiar today as place names. These place names include Daws, Saunder, and Page.
Mill Hill, as with other adjacent areas of Middlesex, was well known for growing hay, a crop which required large numbers of migrant workers during the summer. It may have been that the country sports that were played outside the Kings Head at Whitsun were part of a Whitsun Ale when labour was hired. By 1920 hay ceased to be an important crop, and Mill Hill looked as if it would be swallowed up by the encroaching suburban development. In 1929 Hendon Council purchased more than 50 acres of the Arrandene estate for use as a recreation ground and also to retain Mill Hill Village's distinct character. Famous residents of Mill Hill include William Wilberforce and Sir Stamford Raffles.