The present municipality was formed in 1971, when the market town (köping) Lilla Edet (instituted as late as 1951) was merged with Flundre (part of), Inlands Torpe and Lödöse.

Of these localities, Lödöse is nationally known for being the original location of the city of Gothenburg.

In the medieval age it was a busy city and hosted an important Swedish harbor, until it was moved to its present location in 1473, and little remained.

It has been in operation for some 120 years, and is best known today for its manufacturing of the toilet paper brand "Edet", available in every store in Sweden.

This is a demographic table based on Lilla Edet Municipality's electoral districts in the 2022 Swedish general election sourced from SVT's election platform, in turn taken from SCB official statistics.