Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
FORSYTH
As described in historical dictionaries
Patronymica Britannica (1860)
FORSYTH. Probably from Forcett (whence also Fawcett) a township in the wapentake of Gillingwest, N.R. of Yorkshire.
Origin: Celtic
Region of origin: British Isles
Country of origin: Scotland
Religion of origin: Christian
Language of origin: Gaelic