Last name רידברג (Rydberg 
, Ridberg 
, רידברג 
) , in the entire world, is quite a rare surname. The last name רידברג is characteristic of Northern Europe, particularly Sweden, where it is quite a common surname, Denmark, where it is quite a rare surname, and Finland. Measured by absolute frequency, the name is most common in Sweden, the United States, and Denmark. Very seldom, רידברג is the forename as well as the last name.