Please see our 2025 paper in the Journal of Genetic Genealogy. A copy can be found here: https://www.clanmacleod.org/genealogy/dna-project/dna-of-clan-macleod-paper/

Here is the abstract from this paper:

https://www.jogg.info Page 1 of 22 ©2025. This work is licensed under a CC BY-NC-SA 4.0 license

The DNA of Clan MacLeod
By Mark K. MacLeod¹, Colin Macleod and Roderick A. F. MacLeod
Administrators of the ACMS MacLeod surname project at FTDNA
¹DNA Project Coordinator, Associated Clan MacLeod Societies

Abstract
The powerful MacLeod clan is thought to have originated in the Scottish Highlands in the 13th century. Twenty
years ago, MacLeod clan members started Y-DNA testing to learn more about their origins. By analyzing the
large dataset that has accumulated over these two decades, we found that most MacLeods in the MacLeod
surname project at Family Tree DNA can be placed into one of five genetically distinct subgroups. MacLeods in
the largest of these subgroups are proposed as the patrilineal descendants of the founder of the clan.
Accordingly, the other four genetic subgroups comprise those whose distant ancestors became part of the clan
and assumed the MacLeod surname.

The SNP BY3210 is common to all MacLeods in our proposed founder subgroup. The subsequent formation of
two mutually exclusive descendant SNPs, FTT137 and FTT138, coincides with the traditionally established
split of the chiefly line into two main groups: the Harris & Dunvegan and Lewis & Raasay branches. Several
MacLeods with documented genealogies leading to these two chiefly lines carry SNPs consistent with this split.
On a speculative basis, we have linked several other SNPs to early MacLeods in the chiefly lines. While there
are some noted discrepancies, the estimated age of these SNPs fits with the history of Clan MacLeod.

Autosomal DNA results show that MacLeods crossmatch other MacLeods in all five Y-DNA genetic
subgroups. This suggests that MacLeods who descended from the founder intermarried with MacLeods whose
ancestors assumed the surname. Therefore, most MacLeods in the world today will have a link back to the
founder – either along their paternal line or through a maternal connection in other parts of their family tree.

Four of the five genetic subgroups have origins in different parts of Scandinavia while the fifth subgroup has
Celtic origins. The DNA evidence shows that the MacLeod clan was a melting pot of these diverse groups.
Finally, Y-DNA evidence shows that the founder branch was likely in the Earldom of Orkney before arriving in
Scotland. These Orcadian ancestors originated in Norway, consistent with the traditions of the clan.