Dimnøya, also called Dimna an island in Ulstein Municipality in Møre og Romsdal county, Norway. The island had 1,398 residents in 2014. Dimna is connected to the neighboring island of Hareidlandet to the east by a 20 m wide bridge. The town of Ulsteinvik lies 2 km northeast of the island. The 9 km2 island is about 5 km long and about 4 km wide. It is located about 1 km north of the island of Gurskøy and about 1.5 km north of the island of Leinøy, both in neighboring Herøy Municipality. The club is best known for its sports team Dimna IL, the club of athlete Karsten Warholm.