Family name Du Fay (Du Fay 
) , in all the world, is a very rare surname. The last name Du Fay is characteristic of France, where it is a very rare surname, and the United States, where it is an extremely rare surname.
| VARIANT | COUNTRY |
|---|---|
| Du Fay | United States, France |
| jean du fay French mathematician, FR (b. 1397) |
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charles-jérôme de cisternay du fay French officer, FR (b. 1662) |
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