Here are some options depending on the meaning you want to convey:
If you're looking for a name that sounds similar:
* Alain: A common French name that sounds similar to Allen.
* Allan: A less common French spelling of Allen.
If you're looking for a name with a similar meaning:
* Alain: Meaning "handsome," "noble," or "harmonious"
* Allain: Meaning "handsome" or "noble"
* Laurent: Meaning "laurel" or "victory" (could work if Allen is associated with strength or victory)
If you want to translate "Allen" literally:
* There is no exact translation of "Allen" in French, as it is not a common French name. You could try using the closest-sounding French name or a name with a similar meaning.
Ultimately, the best choice depends on your specific needs and preferences.