In the world, Fidelius (Fidelius 
) is a rare male forename. The first name Fidelius is characteristic of Tanzania, where it is a rare male name, Germany, where it is a very rare male name, and Indonesia. Much less frequently, Fidelius is the last name as well as the forename.
| VARIANT | COUNTRY |
|---|---|
| Fidelius | Germany, Cyprus, Indonesia, Tanzania, France |
| fidelius henselmann German painter, DE (b. 1857) |
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| fidelius schmid DE (b. 1975) |
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