Mors or Morsø is a small island in the shallow sound called Limfjorden in Denmark. It has an area of 367.3 km2 and as of 1 January 2010, it has a population of 21,800. The main town on the island is called Nykøbing Mors. Geologically Mors is unique. Mors, as the neighbouring island of Fur, is known for its deposits of diatomite, locally known as 'moler' (mo-clay).
The development in the number of inhabitants on the island is as follows: