Surname O'Mallon (O'Mallon 
) , across the world, is a very rare cognomen. The family name O'Mallon is characteristic of Australia, where it is a very rare surname, the United States, where it is an extremely rare surname, and the United Kingdom.
| VARIANT | COUNTRY |
|---|---|
| O'Mallon | Australia, United States, United Kingdom |
| simon o'mallon researcher (graduate research school) |
|