Family name Duffill (Duffill 
) , worldwide, is a rare cognomen. The cognomen Duffill is characteristic of the United Kingdom, where it is a rare surname, Australia, and Romania. Measured by absolute frequency, it is commonest in the United Kingdom, Australia, and the United States. Very seldom, Duffill is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Duffill | Romania, United Kingdom, Australia, United States, Canada |
| john duffill British Royal Navy officer, captain in 1846 |
|