The amalgamation leading to the present municipality took place in 1969 when "old" Mellerud (instituted as a market town (köping) in 1908) was merged with Bolstad, Kroppefjäll and Skållerud.

Before the municipal reform of 1952 there were ten entities in the area.

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

[3] In total there were 9,235 residents, including 6,919 Swedish citizens of voting age.

Indicators are in percentage points except population totals and income.