Kungsör Municipality (Swedish: Kungsörs kommun) is a municipality in Västmanland County in central Sweden. Its seat is located in the town of Kungsör.

The present municipality was formed in 1971 when Kungsör and Kung Karl (from which Kungsör had been detached as a market town (köping) in 1907) were amalgamated

Kungsör is located at the western end of lake Mälaren. The landscape is open, dominated by fields and meadows.

Historically, the town grew around the Royal Mansion that King Gustav Vasa had built in the 16th century. Parts of the mansion are still preserved and open for visits. It is located on a cape into the Mälaren.

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

In total there were 8,777 residents, including 6,521 Swedish citizens of voting age. 44.1% voted for the left coalition and 54.8% for the right coalition. Indicators are in percentage points except population totals and income.