The name is first mentioned around 1400 ("i Ræling"). It is probably an old district name (the name of the church site is Fjerdingby). The meaning of the name is unknown.
Coat-of-arms
The coat-of-arms is from modern times. They were granted on 30 April 1981. The arms show a yellow pitchfork on a green background. It is a symbol for the local agriculture. A large part of the municipality is lowland, which historically has mainly been used to produce hay. The pitchfork has three prongs representing the three rivers that run through the municipality: Nitelva, Leira, and Glomma.[4][5]
Number of minorities (1st and 2nd generation) in Rælingen by country of origin in 2015[6]
Located between Fet and Lørenskog, Rælingen includes the northwestern part of lake Øyeren. The northernmost part of the district is built and grown together with the Lillestrøm area.
The most important places in the municipality are Rælingen, Fjerdingby, Løvenstad, and Nordby. Large portions of the municipality are scarcely populated or uninhabited (forests).