Cognomen Diethart (Diethart 
) , around the world, is a rare surname. The last name Diethart is characteristic of Austria, where it is quite a rare surname, Croatia, where it is a very rare surname, and the United States, where it is an extremely rare surname. In absolute terms, it is commonest in Austria, the United States, and Spain. Likewise, Diethart is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Diethart | Austria, Germany, Spain, Canada, United States |
|
thomas diethart Austrian ski jumper, AT (b. 1992) |
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| johannes diethart Austrian author, translator and publisher, AT (b. 1942) |
|
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| roland diethart Austrian cross-country skier, AT (b. 1973) |
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