It is located on the Danubian Lowland, in the region known as Dolné Považie (Lower Váh region) on the Dudváh river, around 45 km east of Slovak capital Bratislava and 8 km from district seat Galanta.

The first written record about the town was in 1252 in a document of King Béla II of Hungary, possibly named after a forest with walnut trees.

Throughout time, the Church, later Erdődys, Esterházys and in the 19th century Zichys owned the town.

Before the establishment of independent Czechoslovakia in 1918, the town was part of Pozsony County within the Kingdom of Hungary.

In 1948 the town was renamed from Diosek to Sládkovičovo in the honor of Andrej Sládkovič, a Slovak poet.