Marchegg (; ; or ; ) is a border town in the district of Gänserndorf in the state of Lower Austria in north-eastern Austria. it is situated on the Morava River on the border with Slovakia. The town is connected to Vysoká pri Morave via a bike bridge. The town was founded by King Ottokar II of Bohemia in 1268.
Local landmarks include the Baroque Marchegg Castle, the Gothic-Baroque Saint Margaret church, and partially preserved medieval town walls.