Family History and Genealogy Resources by Surname
Moon Surname Origin
A corruption of Mohun, or it may be local, from the island Anglesey or Mona, so called, as some suppose, from mwyn, Welsh, mines, from its stone-quarries and mines; others derive it from mon or mona, alone, separated. Mwyn, Welsh, affable, pleasant.
Source: An Etymological Dictionary of Family and Christian Names With an Essay on their Derivation and Import; Arthur, William, M.A.; New York, NY: Sheldon, Blake, Bleeker & CO., 1857.
Moon Surname Meaning and Family Facts
There is more to Moon family history than the origin of your surname:
A Moon Family History Thought:
Whenever there's a will, you'll see an heir loom.