Until 1 January 2007 Nykøbing-Rørvig municipality was a municipality (Danish, kommune) in the former West Zealand County on the northwest coast of the island of Zealand (Sjælland) in Denmark, at the mouth of the Isefjord.
The municipality covered an area of 40 km², and had a total population of 7,610 (2005).
Its last mayor was Vagn Ytte Larsen, a member of the Social Democrats (Socialdemokraterne) political party.
The site of its municipal council is the town of Nykøbing Sjælland.
This create a municipality with an area of 355 km² and a total population of 32,739 (2005).