Maria Wörth is a municipality in the district of Klagenfurt-Land in the Austrian state of Carinthia. The centre of the resort town is situated on a peninsula at the southern shore of the Wörthersee. In the east the municipal area borders the Carinthian capital Klagenfurt. The municipality consists of the two Katastralgemeinden Maria Wörth and Reifnitz (Ribnica).
Maria Wörth is a centre of Austrian and European summer tourism, with 330,000 arrivals (although these numbers have declined sharply since the 1950s). Today's parish church Saints Primus and Felician stands on the highest point of the peninsula, with the neighbouring Winterkirche beneath it. It is a major pilgrimage site and, due to its romantic setting, a popular wedding church. Another tourist attraction is the nearby Pyramidenkogel, an 851-meter high mountain with a 54-meter high observation platform, the Pyramidenkogel Tower.
In 1901 the composer Gustav Mahler built a villa near the hamlet of Maiernigg, on the lakeside in the east of the municipality, where he was already using a "composing hut" in which most of his works written between 1900 and 1907 were composed, including his Symphonies No. 5-8. The hut is now open as a small museum. Through his friendship with Alma Mahler, the composer's widow, Alban Berg also composed at Maiernigg, which was visited by many of the Viennese artistic elite.