Cognomen Mcmannis (Mcmannis 
) , all around the world, is a rare family name. The cognomen Mcmannis is habitual in the United States, where it is a rare surname, Canada, where it is a very rare surname, and Australia. Measured by absolute frequency, it is commonest in the United States, Canada, and the United Kingdom.
| VARIANT | COUNTRY |
|---|---|
| Mcmannis | Brazil, United Kingdom, United States, Australia, Canada |