Köster

Köster is a German surname. It is a variant spelling of "Küster," which designates a sacristan or church caretaker. The role of a Küster historically involved maintaining the church building, its contents, and the surrounding grounds. They were also often responsible for ringing the church bells and assisting the clergy during services.

The surname Köster, like Küster, would have originated as an occupational surname, identifying a family whose ancestor held the position of church caretaker. Over time, the name became hereditary.

The name is primarily found in Germany and areas with significant German immigration, such as the United States, Canada, and Australia.