The Gastein valley was first mentioned as Gastuna in a 963 deed, then part of the Duchy of Bavaria, and was purchased by the Prince-Archbishops of Salzburg in 1297. It was originally a gold mining area and the site of an ancient trade route crossing the main ridge of the Central Eastern Alps. About 1230 the minnesinger Neidhart von Reuental referred to the hot springs in his Middle High German poem Die Graserin in der Gastein, they were visited by Emperor Frederick III as well as by the Renaissance physician Paracelsus.
In the 19th century the waters of Bad Gastein became a fashionable resort, visited by monarchs as well as the rich and famous. Some notable guests of the past included Empress Elisabeth of Austria (Sisi) and the German Emperor Wilhelm I with his chancellor Otto von Bismarck as well as Tsar Ferdinand I of Bulgaria, King Faisal I of Iraq, King Ibn Saud of Saudi Arabia and Iran's last king Mohammad Reza Pahlavi, industrialists like Wilhelm von Opel and artists like Heinrich Mann, Robert Stolz and W. Somerset Maugham. In 1865 Bismarck had signed the Gastein Convention with Austria concerning the administration of the provinces of Schleswig and Holstein after the Second Schleswig War. The composer Franz Schubert is believed to have sketched a score of a Gastein Symphony in 1824. No score of this Gastein Symphony appears to have survived, but it is often identified with the Sonata in C major for piano four-hands (Op. 140, D 812) and/or the Octet in F, D 803.
Mass tourism was pushed by the opening of the Tauern Railway station in 1905. From the 1960s on the resort lost some of its former notoriety and many former hotels sit empty. During the past few years, Bad Gastein renovated its Felsentherme and the Congress Center
