Cognomen Lassenius (Lassenius 
) , in the world, is a rare last name. The family name Lassenius is characteristic of Northern Europe, particularly Finland, where it is quite a rare surname, Sweden, where it is a rare surname, and Denmark. Much less frequently, Lassenius is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Lassenius | Germany, Denmark, Finland, Spain, Sweden |
|
johannes lassenius German author and theologian, DE (b. 1636) |
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| mauritz lassenius (b. 1865) |
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| torbjörn lassenius Finnish decathlete, FI (b. 1931) |
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| johannes lassenius |
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| casper lassenius |
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| pieter lassenius |
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| fredrik lassenius |
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| yvonne lassenius FI |
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