- English and Welsh (very common in southern England and South Wales): patronymic from the medieval English personal name Harry, pet form of Henry.
- This name is also well established in Ireland, taken there principally during the Plantation of Ulster. In some cases, particularly in families coming from County Mayo, both Harris and Harrison can be Anglicized forms of Gaelic Ó hEarchadha.
- Greek: reduced form of the Greek personal name Kharalambos, composed of the elements khara ‘joy’ + lambein ‘to shine’.
- Jewish: Americanized form of any of various like-sounding Jewish names.