Keri (Swedish: Kokskär) is an island in the Gulf of Finland. It belongs to an archipelago of Estonian northern coast together with islands Prangli and Aksi. Keri is approximately 6 km to the north from island Prangli and has a surface area of 3.1 hectares only.

Island Keri was first mentioned in 1623. In 1719 the decision was made to build alighthouse on the island. The today’s lighthouse originates from 1803. Since 2003 Keri does not have permanent inhabitants. The buildings, webcams and events on Keri are managed by Keri Society.