There are many thousand <a href="https://nameberry.com/list/418/Best-Cool-Unusual-Boys-Names">boy names uncommon</a> in the US that are nevertheless widely used in their native lands. Does that mean they're ripe for import? Perhaps. 
 
All of the names on this list rank below the US Top 500. Those rising up the American charts include Idris, Alessio, Monty, and Archie. All of these names could be considered hidden gems, but those that feel especially ripe for American discovery include Viggo, Maxence, Florian, and Cormac. 
 
A rare name will set your son apart from the crowd. The international boy names uncommon in the US but popular in their cultures of origin include the following.
 
<h2>Boy Names Uncommon in the US</h2>

Uncommon Boy Names

This Roman Emperor's name may once have been considered too grand for a baby but in an era of children called Atticus, Augustine, Valentine, Caspian, Thaddeus, and Maximus, Constantine might just be read for a comeback. Briefly popular in the early 1900s in the US, Constantine is better known in other forms: the feminine Constance, for instance, or international variations, such as the French and Romanian Constantin and the Russian, Serbian, Finnish, and Bulgarian Konstantin 
 Derived from the Latin constans meaning "steadfast", it is notably associated with Constantine the Great, the first Roman Emperor to convert to Christianity and issued the Edict of Milan, which proclaimed religious tolerance throughout the empire. Constantine was also the name of three medieval Scottish kings.
 A modern bearer is Constantine Maroulis, singer and actor and American Idol finalist. The 2005 horror film Constantine featured a hero by that surname.
 
Nicknames Conn, Conny, Coco, and Stan might be used.

Constantine

Corentin is an intriguing saint's name fashionable in France but virtually unknown here-- which you may consider a big plus. St. Corentin possessed a magical fish that regenerated itself each night, feeding himself and his lucky visitors in perpetuity.


Corentin

Both offbeat and upbeat, this evocative traditional Irish name that runs through Celtic mythology is known here via award-winning novelist Cormac McCarthy (born Charles). The author's adopted name is related to Cormac Mac Airt, one of the great legendary high kings of Ireland.
 In two of the Harry Potter movies, Cormac McLaggen is a Gryffindor student.
 
A popular choice in Northern Ireland where it made the Top 100 in a recent year, it is also familiar in Ireland (where it last ranked in 2017) and England and Wales where it was given to 26 boys in a recent count. 
 Despite cool nickname Mac, it has never made it onto the US Top 1000, though it has been used by a solid 150 boys in each recent year.

Cormac

Uncommon boy names -- map and paper airplane

Uncommon boy names

Uncommon boy names in the US, rare, unique international  names for baby boys ncluding Alessio, Monty, Viggo, and Cormac, with meanings, origins, and popularity (Page 9)