The settlement of Thale probably emerged at the beginning of the 10th century. It was first mentioned in 936 in connexion with the neighbouring Wendhusen Abbey, which had been founded before 840 as a chapter of canonesses (Kanonissenstift) and was one of the first abbeys on Saxon soil. In the period that followed the abbey came under the guardianship of the chapter in Quedlinburg. The village was described in 1231 as Dat Dorp to dem Dale (from 1288 it was given the description de valle, and from 1303 as von Thale). The abbey was destroyed in 1525 during the Peasants' War.
1912 map of Thale
From 1445 the records show that there had been an ironworks in Thale. It was rebuilt in 1648 after the devastation of the Thirty Years' War as the Berghaus zum Wilden Mann, but was fully destroyed in 1670. In 1686 a small hammer mill was established out of which a new ironworks later developed that benefited especially from its proximity to the ore deposits and the availability of wood. It lasted until 1714. In 1740 a business was opened again. For a short time this ironworks was owned by Frederick the Great. In 1831 the first wrought-iron wagon axle to be made in Germany was manufactured here. In 1835 the oldest sheet steel enamel works in Europe was founded in Thale. Following the town's connexion to the railway network in 1862 with a line to Berlin the place flourished as did the number of workers. Whilst the iron industry had only 350 workers in 1872, by 1905 there were as many as 4,400. In particular, the production of enamel contributed to Thale's international renown; in its heyday Thale produced no less than 10% of the world's production. In 1910 Karl Liebknecht, Rosa Luxemburg and Clara Zetkin spoke to Thale's workers. From 1916 steel helmets were produced in Thale. In the Second World War Thale had the monopoly on this product (from 1934).
Tourism blossomed from the 19th century onwards in connexion with the radon rich water of the Hubertus Spring, which had been opened up in 1836. As a result, various literary figures visited the place, including Heinrich Heine (Die Harzreise) and Theodor Fontane and especially the Bode Gorge. In addition tourists from Berlin enjoyed the summer resort of Thale. This encouraged the connexion of Thale in 1862 to the railway line from Wegeleben. In 1909 a branch line from Blankenburg (Harz) followed. In 1922 the resort was given town rights. From 12 to 14 June 2009 Thale was the venue for the Saxony-Anhalt Day held under the motto Thale sagenhaft ("Legendary Thale"), and attracted around 200,000 visitors.
Warnstedt was incorporated in 2003. In 2009 a total of seven municipalities were incorporated on four separate dates. Westerhausen was added in 2010. Allrode became a part of the borough of Thale in 2011.
Since 1990 Thale has had a town partnership with Seesen (Lower Saxony) on the northwest edge of the Harz and, since 1998, with the French town of Juvisy-sur-Orge, 18 km from Paris, as well as Tillabéri in Niger, northwest of the River Niger.