Surname Duffan (Duffan 
) , all around the world, is a very rare last name. The last name Duffan is habitual in the United States, where it is an extremely rare surname, Canada, and Argentina. Much less frequently, Duffan is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Duffan | Spain, Argentina, Canada, United States |