Family name Firminus (Firmin 
, Firmino 
, Firminus 
) , around the world, is a common last name. The surname Firminus is habitual in Cabo Verde, where it is quite a common surname, Brazil, and Portugal. Not in comparison with a country's population, it is the most numerous in Brazil, Angola, and France. Likewise, Firminus is the forename as well as the last name.