Koster

Koster is a surname of Dutch, German, and Swedish origin. It appears in several European and North American countries and has variants such as Koester and Köster. The name is commonly considered habitational or occupational, and it appears in historical records dating back to the medieval period. Today it is carried by people across many fields, with no single figure controlling prominence in a given context.

In geography, Koster most prominently refers to the Koster Islands (Kosteröarna) in Bohuslän, Sweden. This archipelago lies off the coast near Strömstad and comprises North Koster, South Koster, and numerous smaller islets. The islands are known for their rugged coastline, boreal flora and fauna, and diverse marine life. They are a popular tourist destination, accessible by ferry from Strömstad and hosting nature reserves, walking routes, and visitor facilities that accommodate seasonal and year-round visitors.

Other uses include toponymic applications in various countries and its adoption as a family name for organizations and businesses. As a general term, Koster can therefore refer to people, places, and entities connected by the shared surname or place-based origins, reflecting its broad geographic and cultural reach.