[7] The municipality (originally the parish) is named after the Midsundet (Old Norse: Miðjusund), the strait that flows between the islands of Otrøya and Midøya.

The official blazon is "Azure, two triangles argent the lower reversed" (Norwegian: På blå grunn to sølv trekantar, den nedste vend nedover).

This means the arms have a blue field (background) and the charge is two triangles one over the other so that they look like a mirror image.

The triangles have a tincture of argent which means they are commonly colored white, but if the arms are made out of metal, then silver is used.

The three largest islands of the community lie in a line from ENE to WSW (Otrøya, Midøya, and Dryna).

The southern coasts of Otrøya, Midøya, and Dryna rise from the fjord as sheer 800-metre (2,600 ft) tall cliffs.

On the southern coast of Otrøya the following small villages can be found: (from east to west) Solholmen, Nord-Heggdal, Oppstad, Sør-Heggdal, and Klauset.

The north has the following villages: (east to west) Ræstad, Rakvåg, Tangen, Raknes, and Uglvik.

On the western side of Otrøya, facing the bay that separates it from Midøya, lies the village of Midsund, the largest settlement in the community.

The larger three islands' interior is wilderness, but the rims are used for keeping cattle and small farming.

The municipal council (Kommunestyre) of Midsund is made up of 17 representatives that are elected to four year terms.