Lørenskog 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 Lørenskog. Lørenskog was separated from the municipality of Skedsmo on 1 January 1908.
The municipality (originally the parish) is named after the old (and no longer existent) Leirheimr farm. The first element is leirr which means "clay" and the last element is heimr which means "homestead" or "farm". Thus: "the farm built on clay ground". The suffix skógr (meaning "wood") was added later, changing the meaning to "the woodlands around the farm Leirheimr". Prior to 1918, the name was spelled "Lørenskogen".
Lørenskog's arms date from modern times. Granted on 26 July 1957, they show a red waterwheel on a gold background. Water-driven sawmills were once an important part of the municipality's economy.
The municipality is located just east of the capital, Oslo, with many main roads going through it. Almost all the inhabitants live in the northern part of Lørenskog. The southern parts consist of forest, while farms and grain fields occupy the space in between. An important train station, Lørenskog Station, is situated in the district. Within Lørenskog, Losby is known for its waterwheel, which is represented in the municipal coat-of-arms of Lørenskog. Losby Golf and Country Club is located within the municipality.