The origin(s) of the Clann Mackinlay are not well substantiated and, likely, quite diverse. In fact, it should be clarified that the surname, Mackinlay, represents a proud line, to be sure, but only a clann in the traditional Gaelic sense of "family". It certainly does not represent an organized Clan in and of itself but rather a sept of one or more of the Highland Clans described at the end of this paragraph. It is certainly one of those clanns about which we have no definite account. The English form of Mackinlay, unlike Macinnes but like MacKay, has had a "k" inserted where it does not belong, because Mackinlay derives from Mac Fhionnlaigh or Son of Finlay. The letter "k" is foreign to Gaelic but was introduced into Mackinlay, Mackay, Mackerracher, Mackinnon and other surnames to meet the demands of English orthography. The Mackinlay appellation is in the style of the Farquharson chiefs. However, curiously, the clan of Finla Mor does not use this surname in the Braes of Mar. It is mostly among those of Finla Mor's descendants who emigrated to the Lowlands that the names of Finlay, Findlayson and Mackinlay came into currency. In Lochalsh and Kintail, the surname of Mac Fhionnlaigh in Gaelic and Finlayson in English derive also from the parent stem of the Farquharsons of Braemar. However, the Records of Invercauld make it quite clear that at least some Mackinlays were an outgrowth of the early Farquharsons. In addition, Tranter, in Lord in Waiting, refers to a story based on oral tradition that describes the Mackinlays of Bute as having been banished to Perthshire by Robert I ("The Bruce") . The Court of the Lord Lyon has acknowledged that Mackinlay is a sept of Clan Farquharson, while conceding that it is not infrequent for a relatively common surname to be found as a sept of more than one clan. As further elucidated below, William Buchanan of Auchmar identifies Clans Buchanan and MacFarlane, as well as Clan Stewart of Appin to lay claim to Mackinlays in the more western parts of Scotland.

It has been asserted that the principal stock of Mackinlay has been ascribed to the Lennox: "There can be little doubt the county of the clan was in the Lennox district, where we find them yet in great numbers. The oldest account of them is given by Buchanan of Auchmar, 1723. He asserts that the sept of the Lennox Mackinlays was descended from Buchanan of Drummikill. After mentioning that the Risks were¦ (among the cadets "of other denominations')" of the Drummikill family, he (Auchmar) states, 'The second cadets of this kind are the MacKinlays, so named from a son of Drumikill, called Finlay; those lately in Blairnyle and about Bellach are of this fort, as also those in Bemachra, and about the water of Finn in Lufs-parish. The Mackinlays in some other parts of these parishes are MacFarlanes'. It is probable the name Mackinlay embraces some of the Macleay Clan."

The Gaelic rendering of Livingstone, Mac-an-Leigh, applied to the name in Lismore and Appin, and anglicized as Maclay or Mackinlay, are accepted by the Stewarts of Appin. There were at one time several Mac-an-Leighs in Dunbartonshire, and farther north were the Mac-on-Leays, the real Macleays. In fact,Clan Mac an Ollamh (Gaelic), but Clan Maclea (English) is thought to also represent the Highland branch of the Livingstones, to which there have been some Mackinlays with sept allegiance. Clan Stewart of Appin is interesting in that it is one of three non-royal, Stewart clans. It derives its origin from Alexander, 4th High Steward of Scotland who, in turn, begat Sir John Stewart of Bonkyl. Sir John inherited Castle Stalcair, which had been occasionally used as a royal hunting lodge by James IV. The Appin Stewarts were "out" in 1715 for the Old Pretender and fought at the Battle of Sheriffmuir. Charles Stewart led the Appin men at Culloden in 1745, 92 of 300 having been killed, but not before distinguishing themselves by breaking through the Redcoats' ranks.

The Mackinlays who settled at "The Annie", in the Pass of Leny, near Callander in Perthshire, claim descent from Finla Mor Farquharson of Braemar, although the genealogical tree of Finla Mor Farquharson fails to reveal any surviving male issue of the sons of his first marriage. The name Mackinlay has occurred most commonly in record in Glen Lyon and in Balquhidder, but also in Perthshire. Additionally, the Mackintoshes of Cam on the River Shee are also known as "alias, Macinlies". McInlie here is equal to Mac Fhionnlaigh, although it occurs in RPC.xi, as Macleith, McCleich, McKinleiche, and McIlleich. It is singular that no Mackinlay is recorded in all the lists of the 1745 rebels. The Standing Council of Scottish Chiefs has recognized the following relationships between these clans and the family of Mackinlay

The Standing Council of Scottish Chiefs has recognized the following relationships between these clans and the family of Mackinlay;

Reference: http://homepages.rootsweb.ancestry.com/~mckinlay/