Surname Tostus (Tost 
, Tosto 
, Tostus 
) , throughout the world, is quite a common last name. The last name Tostus is characteristic of Italy, where it is quite a rare surname, Germany, and Denmark. Measured by absolute frequency, the name is most common in Germany, Italy, and the United States. Much less frequently, Tostus is the forename as well as the last name.