Sørum is a municipality in Akershus county, Norway. It is part of the traditional region of Romerike. The administrative centre of the municipality is the village of Sørumsand. Sørum was established as a municipality on 1 January 1838 (see formannskapsdistrikt). The municipality of Blaker was merged with Sørum on 1 January 1962.
The municipality (originally the parish) is named after the old Sørum farm (Old Norse: Suđrheimr), since the first church was built here. The first element is suđr which means "southern" and the last element is heimr which means "home/homestead" or "farm".The coat-of-arms is from modern times. They were granted on 26 June 1981. The arms show a red rose with five petals on a yellow background. The rose is derived from the arms of the medieval dynasty of Sudreim (Sudreimsætten), one of the most influential noble families in Norway at the Time. Their name was derived from what is now known as Sørum.