As described in historical dictionaries

An Etymological Dictionary of Family and Christian Names (1857)

(origin: Local) Living near a mill. Gaelic, Milidh, a soldier, the d being silent.

Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.


Patronymica Britannica (1860)

MILLS. Perhaps from residence near mills, in some instances. I am rather disposed, however, to consider it the genitive of an abbreA-iatcd form of Michael (see l\Iiles), and the occurrence of Millson seems to favour this derivation. But see Milsou, which is ' local.'

Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.


Origin: English

Region of origin: British Isles

Country of origin: England

Religion of origin: Christian

Language of origin: English

BritishSurnames.uk is a Good Stuff website.