Origins of McGeorge/MacGeorge

There are a number of theories about the origins of the McGeorge name.

  There are several Clans which have McGeorge as septs
Clan Buchanan 
http://www.tartans.com/clans/buchanan/buchanan.html  
Clan Gunn http://www.tartans.com/clans/gunn/gunn.html
and Clan Dewar.

Another explanation:
Extracts from the book "Scottish Nations" 1868
"MacGeorge, originally Mac Jore, the surname of an old family which, from an early period, was settled in Galloway.  Towards the middle of the 17th century they had become divided into several branches - all landed proprietors and all in the same district, chiefly in the parish of Urr
One of these branches was Macgeorge of Cocklick, another Macgeorge of Culloch, and a third became proprietors afterwards of the lands of Auchenroeach and others. The name, at an early period spelt and pronounced Macjore, appears in that form on  of the tombstone of one of the families is interesting as showing the change in the writing of the name in the same family. It is as follows "John Macjore in Cartine died 28 Feb 1691, age 80: also John McGeorge of Cocklick his son. He died 17th June 1726 aged 69"....."
"The late Mr Brydson , the author of an excellent  book on heraldry, is of opinion that the family of Macgeorge was descended  from the Irish Clan of MacIoris which had settled, he says at an early period, in Galloway and which, in time of Henry II was reckoned among the great families of Ireland. This confirmed by the manner in which the name at an early period was pronounced and spelt in Galloway...."

Extracts from .....?? (name to be added )
"Peirs de Bermingham, Lord of Thetmoy in Offaley, is usually reckoned the 1st Baron of  Athenry, and was the progenitor of this family, which was known to the Irish as MacFeoris (MacPierce), in consequence of their descent from him. Throughout the whole of 'the Annals of the Four Masters' the name Bermingham never once occurs; notices of the family are very frequent but always under the adopted Celtic name of MacFeoris. From this ancient family of the Bermingham is descended a branch settled in Scotland which still retains this old Celtic name of MacJoris, or as they began to write it in the beginning of the 18th century, MacGeorge."

Urr is a parish within Kirkcudbrightshire, Scotland.

From my own research I have several variations of the name in early  Galloway (Kirkcudbrightshire and Wigtownshire Scotland) and Dumfriesshire...  MacJor, MacJore, McGore.  Some of the families settled on calling themselves MacGeorge and others McGeorge.  A couple of families were orginally George from Ayrshire (an adjoining county ) and then became McGeorge. One of these went to Australia and became McGeorge about 2 years later.  I have found that most McGeorge's who emigrated, originally came from this area

I have compiled large family trees on these first McGeorge families for more details please email me.