Eiker is a traditional district in the county of Buskerud, Norway.

The area is located in the southern part of Buskerud county.

During the early Viking Age, Eiker was the western extension of the kingdom of Vingulmark.

The parish of Eker was established as a municipality on 1 January 1838 (see formannskapsdistrikt).

The church was built of stone fracture in lime mortar and plastered inside.