Rømø (German: Röm, North Frisian: Rem) is a Danish island in the Wadden Sea. Rømø is part of Tønder municipality. The island has 650 inhabitants as of 1 January 2011 and covers an area of 129 km². Rømø is a popular spot for tourists attracted by the nudist beaches which can be driven onto legally with motor vehicles.
Rømø is now the southernmost of Denmark's Wadden Sea Islands (the previous being the small uninhabited island of Jordsand which sank in 1999). It is linked to the Danish mainland by a road running across a causeway, and the island lies about 3 km from the neighbouring German island Sylt, to which it is connected by ferry. It is home to a number of small communities such as Kongsmark, Østerby, Lakolk, and Sønderstrand.