Family name Derfl (Derfl 
) , in the world, is a very rare cognomen. The family name Derfl is habitual in Czechia, where it is a rare surname, Croatia, and the United States, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Derfl | Czechia, United States, Croatia |
| jaroslav derfl CZ (b. 1906) |
|
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| bohumil derfl (b. 1911) |
|
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| antonín derfl CZ (b. 1918) |
|