The Irish and Scottish surname McKeag is an anglicized form of the Gaelic name Mac Thaidhg (Scottish Gaelic Mac Thaoig) meaning “son of Tadhg,” a personal  name meaning  “poet, or philosopher.” When found in Ireland the name is from county Galway in the west of the country and when found in Scotland it is confined to Ayr and Galloway. Over the centuries MacThaidhg has acquired a number of spellings including: MacCaig, MacCague, MacKaig, MacKeeg, MacKeig, McKeag, MacKegg, MacKeague and Caig, the last mentioned form being widespread in Galloway and Ulster. Amongst the early recordings are those of Andrew McCaig in the Scottish Acts of Parliament dated 1567, and Jennat Mackcaige in the Register of the Privy Council of Scotland in 1685. Today in the US there are approximately 300 bearers of the name McKeag.