The present municipality was formed in 1971 through the amalgamation of three former units. Before the subdivision reform of 1952, there were seven entities in the area.
The parish is named after the old farm Tanum (NorseTúnheimr), since the first church was built there. The first element istún 'countrycourtyard', the last element is heimr 'homestead, farm'.
This is a demographic table based on Tanum Municipality's electoral districts in the2022 Swedish general election sourced fromSVT's election platform, in turn taken fromSCB official statistics.[4]
In total there were 12,959 residents, including 10,274 Swedish citizens of voting age.[4] 41.4% voted for the left coalition and 57.5% for the right coalition. Indicators are in percentage points except population totals and income.