Surname Katiin (Curtain 
, Courtine 
, Katiin) , worldwide, is quite a rare cognomen. The surname Katiin is habitual in Jersey, where it is quite a common surname, Australia, where it is quite a rare surname, and Switzerland. Measured by absolute frequency, it is commonest in France, Australia, and the United States. Very seldom, Katiin is the forename as well as the last name.