It is based on a place name derived from Old English heg "hay" and leah "clearing or meadow",[1] The surname Haley was found in County Sligo (Irish: Sligeach), in the province of Connacht in Northwestern Ireland, where they held a family seat from ancient times.
The original form of Haley is O hEalaighthe, which is derived from the word "ealadhach," which means "ingenious."
Another Gaelic form of the surname is O hEilidhe, which is derived from the word "eilidhe," which means "claimant".
Variant spellings include Heily, Hailey, Hayley, and Healy.
[1] The family name Haley is also a variant spelling of the anglicized Irish Healy (surname).