Surname Mcilwrath (Mcilwrath 
) , worldwide, is a rare family name. The family name Mcilwrath is characteristic of the United Kingdom, where it is a rare surname, Ireland, and New Zealand. In absolute terms, it most frequently occurs in the United Kingdom, the United States, and Canada.
| VARIANT | COUNTRY |
|---|---|
| Mcilwrath | Canada, Australia, United States, United Kingdom, Ireland |