Surname Istvanne (Istvanne 
, Истванне 
) , in all the world, is a rare last name. The last name Istvanne is habitual in Hungary, where it is quite a rare surname, Denmark, where it is a rare surname, and Romania. In absolute terms, the name is most common in Hungary, Romania, and Austria. More frequently, Istvanne is the forename as well as the last name.