Mersch (French pronunciation: [mɛʁʃ], German pronunciation: [mɛʁʃ]; Luxembourgish: Miersch [ˈmiːɐ̯ʃ] ⓘ) is a commune and town in central Luxembourg, situated in the canton of the same name.

As of 2023[update], the town of Mersch, which lies in the centre of the commune, has a population of 5,093.

Other towns within the commune include Beringen, Berschbach, Moesdorf, Pettingen, Reckange, Rollingen, and Schoenfels.

The town is the site of one of the six regional headquarters of the Grand Ducal Police.

Today the castle houses the administrative offices of the local commune.