Ishøj is a Danish town with a population of 21,269. It is situated in the Region Hovedstaden, and is the seat of the Ishøj Municipality.

Ishøj Municipality is a municipality in the Capital Region on the island of Zealand (Sjælland) in eastern Denmark. The municipality covers 26 km², with a total population of 23,457. Its mayor is Merete Amdisen, a member of the Social Democrats (Socialdemokraterne) political party.