Sankt Goar is a town on the west bank of the Middle Rhine in the Rhein-Hunsrück-Kreis (district) in Rhineland-Palatinate, Germany. It belongs to the Verbandsgemeinde of Sankt Goar-Oberwesel, whose seat is in the town of Oberwesel.

Sankt Goar is well known for its central location in the Rhine Gorge, a UNESCO World Heritage Site since July 2002. Above the town stand the ruins of Burg Rheinfels, one of the castles for which the Middle Rhine is famous, and across the river lies the sister town of Sankt Goarshausen with its own castles, Katz and Maus (“Cat” and “Mouse”). The famous Lorelei rock is close-by, slightly upstream on the opposite bank.