The administrative centre of the old municipality was the village of Bjølstad where the Heidal Church is located.

[5] The municipality of Heidal (originally spelled Hedalen) was established on 1 January 1908.

[6] During the 1960s, there were many municipal mergers across Norway due to the work of the Schei Committee.

On 3 November 1917, a royal resolution changed the spelling of the name of the municipality to Heidal, adding an "i" and removing the definite form ending -en.

The mayor was indirectly elected by a vote of the municipal council.