Harrell was established as a surname in England by Normans following the conquest in 1066; the earliest recorded use is in an abbey charter in 1154 where it is spelled "Horel". The surnname appears to be derived from the Old French verb "hurer" meaning to bristle or stand up, and was most likely a nickname for someone with a good head of hair. Harrell may be recorded as one of several variants such as Hurran, Hurren, Harrill, Horrell, Horel, Hurrell, Arrell and Orrell. Harrell is not related in meaning or etymology to the given name Harold, which is from Old Norse, meaning army commander.
The surname Harrell also appears in Ireland where it may be an anglicized form of the Gaelic name Ó hEarghail 'descendant of Earghal'. Earghal was a given name with the same etymology as Fearghal, which may be anglicized as Fergal but is also the source of the surname Farrell. Fearghal was a popular given name for boys meaning manly or valorous in early Ireland.