Its twin sister-town across the Salzach Bridge is Laufen in Bavaria. The town was split in two in the wake of the Napoleonic Wars when the former Principality of the Salzburg Archbishops was divided in 1816 following the Congress of Vienna into a part taken by the Kingdom of Bavaria and a part taken by the Austrian Empire.
Oberndorf is famous worldwide as the birthplace of the carol Silent Night (German: Stille Nacht), which was first performed at the former St. Nikola parish church by the schoolmaster Franz Xaver Gruber and the young priest Joseph Mohr on Christmas Eve 1818, from where it spread out to the world. As in the 1890s several floods of the Salzach River destroyed large parts of Oberndorf, the church was finally demolished and a memorial chapel erected on its site in 1937. A replica can be found in Frankenmuth, Michigan.
Oberndorf can be reached from Salzburg by S-Bahn rapid transit railway and the B 156 Lamprechtshausener Straße federal highway running from Salzburg toward Braunau am Inn.