Family name Guelsy (Guelsy 
) , worldwide, is an extremely rare last name. The cognomen Guelsy is habitual in Latin America and the Caribbean, particularly Nicaragua, where it is a very rare surname, Honduras, and Venezuela, where it is an extremely rare surname. In absolute terms, it most frequently occurs in Latin America and the Caribbean, particularly Mexico, Nicaragua, and Honduras. More prevalently, Guelsy is the forename as well as the last name.