Cognomen Casasus (Casasus 
) , across the world, is a rare last name. The cognomen Casasus is characteristic of Spain, where it is a rare surname, Mexico, and France, where it is a very rare surname. Measured by absolute frequency, this name is the most popular in Spain, Mexico, and Philippines. Much less frequently, Casasus is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Casasus | Philippines, France, Spain, United States, Mexico |
|
joaquin demetrio casasus Mexican Ambassador to America around 1910, MX (b. 1858) |
|
| gilbert casasus political scientist (b. 1956) |
|
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| maximo plo casasus Spanish particle physicist |
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