Gray is a surname of that can come from a variety of origins but is typically found in Scotland, Ireland and England.
In Ireland, the surname may have a Gaelic source from a phonetic transcription, or Anglicization of or McGraw. "Mac Giolla Riabhaigh" is sometimes Gray, but is also Anglicized to "McGreevy," "Gallery" and others.
In most Scottish instances, the name "Gray" is from the Germanic Scots language, and is cognate with Old English, "græg", meaning "grey", probably as a hair colour.
Also among Irish and Scottish Grays is the English name of Anglo-Norman origin. A knight of Viking origin, Anchetil de Greye, accompanied William the Conqueror in his 1066 invasion of England. de Greye's descendants would become bishops John de Gray of Norwich and Walter de Gray of York.