Cognomen Mcfarlen (Mcfarlen 
) , throughout the world, is a rare family name. The cognomen Mcfarlen is characteristic of Canada, where it is a rare surname, New Zealand, and the United States, where it is a very rare surname. Not in comparison with a country's population, it is commonest in the United States, Canada, and the United Kingdom.
| VARIANT | COUNTRY |
|---|---|
| Mcfarlen | United Kingdom, New Zealand, United States, Canada |