Tags: Name, Surname.
Loudin is a French surname. It came to be known as Loudon among immigrants to Scotland (the Loudon clan is a subset of the Campbell clan). Americans with the surname Loudin mostly live in the midwest and are of Scots-Irish descent.Loudin/Loudon/Lowden etc. are also spellings of Lothian the Scottish county and it is more likely that the Scots surname came from this.Loudoun Castle in Ayrshire is apparently the same place-name and some instances will have come from that area.