Cognomen Mactiernan (Mactiernan 
) , worldwide, is a very rare surname. The cognomen Mactiernan is characteristic of Australia, where it is a rare surname, the United States, where it is an extremely rare surname, and the United Kingdom.
| VARIANT | COUNTRY |
|---|---|
| Mactiernan | United Kingdom, United States, Australia |
|
alannah mactiernan Australian politician, AU (b. 1953) |
|