The first mention of "Sumbotheil" (English: "Saturday market") dates back to 1209. In the mid-13th century, the town was destroyed by the Mongols, and by 1282 under the name "Niusidel" resettled. In 1517 Neusiedl received market rights. Neusiedl in 1683 was in the wake of the second Turkish siege, and in 1708 the town was devastated by the Kuruc. Neusiedl am See received a city charter in 1926, which had already been investigated in 1824.
The place was, like the rest of Burgenland, with Hungary until 1920/21 (German West Hungary). After the end of World War I, it was awarded after tough negotiations, German West Hungary in the Treaty of St. Germain and Trianon, Austria 1919. The place has belonged since 1921 to the newly founded State of Burgenland (see also history of Burgenland).