Mattersburg (German pronunciation: [ˈmatɐsˌbʊʁk] ⓘ; formerly Mattersdorf, Hungarian: Nagymarton, Croatian: Matrštof) is a town in Burgenland, Austria.

Mattersburg lies in the northern part of Burgenland, east of Wiener Neustadt in the Wulka River Valley, in a rural region of the country.

During the 19th century, the town was the site of a ceramics factory founded by János Ziegler in 1815 or 1818, producing yellow coloured wares following the style of Vienna porcelain.

As with the rest of Burgenland, Mattersburg belonged to the Kingdom of Hungary until 1920 and it was the seat of the Nagymarton district in Sopron county.

In late 1918, Mattersburg locals rebelled against Hungarian rule to create the short-lived Republic of Heinzenland aimed at unifying with Austria.

After the end of the First World War, German West-Hungary was given to Austria in the Treaties of St. Germain and Trianon; there it formed the new province of Burgenland.