The name is at least from the fifteenth century, referring to a bay by the small lake Hyn, where the church was constructed.

The town later became the seat of the juridical Kil Hundred, which is known to have existed in 1426.

This is a demographic table based on Kil 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 12,129 residents, including 9,297 Swedish citizens of voting age.

Indicators are in percentage points except population totals and income.