Family History and Genealogy Resources by Surname
Trevelyan Surname Origin
(Origin Cornish British) Trevellyan, the town of the mill. Welsh, Tremelin, or Trevelin.
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.
Trevelyan Surname Meaning and Family Facts
There is more to Trevelyan family history than the origin of your surname:
A Trevelyan Family History Thought:
'Those who forget their past are destined to repeat it.' --Robert A. Heinlein