Midsund is a municipality in Møre og Romsdal county, Norway. It is part of the Romsdal region. The administrative centre is the village of Midsund on Otrøya island. The municipality consists of the islands of Otrøya, Midøya, Dryna, and the smaller (<1 km) islands of Magerøya and Tautra. The islands all sit at the mouth of the great Romsdalsfjord.
The municipality of Midsund was established on 1 January 1965 when the old municipality of Sør-Aukra (population: 1,912) was merged together with part of Midøya island and the neighboring island of Dryna (population: 334) which were part of Vatne municipality.
The coat-of-arms is from modern times. They were granted on 15 May 1987. The arms show two silver triangles on a blue background, representing Otrøya and Midøya islands in the ocean. These two main islands in the municipality are separated by a small strait, the Midsund. The geographical situation is symbolised in the arms.