Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
WALLACE
As described in historical dictionaries
Patronymica Britannica (1860)
WALLACE. Though resembling, very closely, the Walleys and Wallis of English family nomenclature, this surname may have a distinct origin. It appears to have been anciently a personal name. Galgacus, the celebrated Caledonian chief, Avho opposed the arms of Agricola, has been identified by Baxter with Gwallog, a British name, and this has been suggested as the original form of the modern Wallace. See Gentleman's Mag. March, 185G, p. 218.
Surname type: From given name or forename
Origin: Celtic
Region of origin: British Isles
Country of origin: Scotland
Religion of origin: Christian
Language of origin: Gaelic