Rælingen is a village and municipality in Akershus county, Norway. It is part of the traditional region of Romerike. The administrative centre of the municipality is the village of Fjerdingby. Rælingen was separated from the municipality of Fet on 1 July 1929.

Lillestrøm is a municipality in Akershus county. It is located in the traditional district of Romerike. With a population of 85,757 inhabitants, it is the fourth most populated municipality in Viken. It was founded on 1 January 2020 as a merger between former municipalities Fet, Skedsmo and Sørum. The administrative centre of the municipality is the town of Lillestrøm. The town of Lillestrøm is a part of the Oslo metropolitan area.