The name means "the little Str�m", Str�m being the name of an old and large farm (Old Norse: straumr, which also meant "stream" as well).
Lillestr�m's history dates back to the times river powered sawmills came into use for the production of building materials. Later Lillestr�m got its own steam sawmill which laid the base for the development of the area which became the town. The area was, by and large, a moss covered swamp-like area, at the time considered almost uninhabitable. However, the almost non-existent property values were judged to be a fair exchange and so the workers started living and settling in the area around the sawmill, and Lillestr�m was born.
On January 1, 1908, Lillestr�m became a municipality of its own, having been split from Skedsmo. At that time Lillestr�m municipality had a population of 4,351. On 1 January 1962 the two municipalities were reunited under the name Skedsmo. Before the merger Lillestr�m municipality had a population of 10,840.
As of 1997, Lillestr�m is a city in its own right. Since then, Lillestr�m holds an annual 4 day city fair, which is entirely free of charge. It includes music by high profile Norwegian artists on several outdoor stages, food, retail business exhibitions and thrill rides en masse. Everything is held in Lillestr�m's main street and the connecting streets, which is reserved for pedestrians for the occasion.
In 2002, Norway Trade Fairs moved from Sk�yen to Lillestr�m
