Family name Rēx (Rey 
, Re , Regat 
) , across the world, is a widespread last name. The cognomen Rēx is characteristic of Monaco, where it is a common surname, Uruguay, where it is quite a common surname, and Mauritius (explore the name in all countries). Measured by absolute frequency, the name is most common in Colombia, France, and Mexico. Also, Rēx is the forename as well as the last name.