Kostolná pri Dunaji (Hungarian: Egyházfa, meaning Church Tree, Slovak: Kostolná pri Dunaji, meaning "Churchville by the Danube") is a village and municipality in western Slovakia in Senec District in the Bratislava Region.

The municipality lies at an altitude of 128 metres and covers an area of 8.072 km².

In historical records the village was first mentioned in 1332.

After the Austro-Hungarian army disintegrated in November 1918, Czechoslovak troops occupied the area, later acknowledged internationally by the Treaty of Trianon.

Between 1938 and 1945 Kostolná pri Dunaji once more became occupied by Miklós Horthy's Hungary through the First Vienna Award.