Rottumeroog (Dutch pronunciation: [ˌrɔtʏmərˈoːx] ⓘ; West Frisian: Rottumereach) is an uninhabited island in the Wadden Sea and is part of the Netherlands.

Rottumeroog is now part of the natural reserve Rottum and access to the island is prohibited, save for people with a special permit.

Rottumeroog does not have a solid core and slowly moves in southeastern direction as a result of sea currents.

After the Protestant Reformation the island's rights transferred to the province Groningen before being sold to private persons in the 17th century.

Between 1706 and 1717, Donough MacCarthy, 4th Earl of Clancarty, having been banished from Ireland, owned and lived on the island.

[8] The Wadden Sea, in which Rottumeroog is situated, is a UNESCO World Heritage Site (natural criteria viii, ix, and x) since 2009.