Ørskog is a former municipality in Møre og Romsdal county, Norway. The 133-square-kilometre (51 sq mi) municipality existed from 1838 until its dissolution in 2020. The area is now part of Ålesund Municipality in the traditional district of Sunnmøre. The administrative centre was the village of Sjøholt. The other main village was Vaksvika, about 7.5 kilometres (4.7 mi) south of Sjøholt. The European Route E39/E136 highway ran through the municipality, connecting the towns of Ålesund and Molde. The Rauma Group was the largest company in Ørskog in terms of turnover.

Prior to its dissolution in 2020, the 132.69-square-kilometre (51.23 sq mi) municipality was the 363rd largest by area out of the 422 municipalities in Norway. Ørskog Municipality was the 310th most populous municipality in Norway with a population of about 2,250. The municipality's population density was 17 inhabitants per square kilometre (44/sq mi) and its population had increased by 5% over the previous 10-year period.

Ørskog was established as a municipality on 1 January 1838 (see formannskapsdistrikt law). On 1 August 1883, the southwestern district of Ørskog (most of Ørskog on the southwestern side of the Storfjorden except for the Søvik and Ramstaddalen areas) was separated to form the new Søkelven Municipality (the spelling was later changed to Sykkylven). This left Ørskog Municipality with 1,735 inhabitants. On 1 June 1955, the Søvik and Ramstaddalen areas of Ørskog Municipality (located south of the Storfjorden) were administratively transferred to Sykkylven Municipality.

During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee. On 1 January 1965, there was a merger between three neighbors: Stordal Municipality (population: 1,052) in the south, Ørskog Municipality (population: 1,664) in the centre, and Skodje Municipality (population: 2,048) in the north, creating a new, larger Ørskog Municipality. This was merger was short-lived. On 1 January 1977, the merger was reversed all three municipalities were separated once again. This left the newly reconstituted Ørskog Municipality with a population of 1,668.

On 1 January 2020, Ørskog Municipality was merged with Haram Municipality, Skodje Municipality, Sandøy Municipality, and Ålesund Municipality to form a new, larger Ålesund Municipality.

The municipality (originally the parish) is named after the old Ørskog farm (Old Norse: Øyraskógr) since the first Ørskog Church was built there. The first element is the plural genitive case of eyrr which means "gravel shoal near the mouth of a river". The last element is skógr which means "wood" or "forest".

The coat of arms was granted on 11 November 1983. The official blazon is "Ermine, a pale Or" (Norwegian: På hermelin grunn ein gull pæl). This means the arms have a field (background) has a tincture of ermine which means it is commonly colored white with small black spots. The charge is a pale with a tincture of Or which means it is commonly colored yellow, but if it is made out of metal, then gold is used. The pale was chosen to symbolize a tree trunk, as a symbol for forestry. In the 17th century, the municipality exported many tall trees to the Dutch Republic, where they were used for shipbuilding. The ermine background was chosen to symbolize fur farming in the area as well. The ermine is also a canting for the many animals in the forests. The arms were designed by Jarle Skuseth. The municipal flag has the same design as the coat of arms.

The Church of Norway had one parish (sokn) within Ørskog Municipality. It was part of the Austre Sunnmøre prosti (deanery) in the Diocese of Møre.