Herschbach (German pronunciation: [ˈhɛʁʃbax]) is a state-recognized “air” health resort (Luftkurort) in the Westerwaldkreis and the biggest Ortsgemeinde – a community belonging to a Verbandsgemeinde – in the Verbandsgemeinde of Selters, in Rhineland-Palatinate, Germany.

Herschbach is found in the Dierdorf Hollow, which is itself nestled in the hilly low mountain region of the lower Westerwald halfway between Cologne and Frankfurt am Main. The municipal area is home to three conservation areas (Naturschutzgebiete) as well as an 800-ha community forest. Right nearby is the Westerwald Lake Plateau on which rises the Holzbach, which also flows through the municipal area.

Bordering on the community are, clockwise beginning in the north, Mündersbach (3 km), Schenkelberg (3 km), Hartenfels (3 km), Rückeroth (1 km), Marienrachdorf (3 km) and Freirachdorf (2 km). The nearest towns are Selters (6 km to the south), Dierdorf (7 km to the west) and Hachenburg (14 km to the north). Koblenz (35 km to the southwest), Siegen (51 km to the northeast) and Bonn (60 km to the northwest) are the nearest cities.

Written records about Herschbach begin with its first documentary mention in 1248. It can be assumed, however, that the area had already been settled long before that, as a place named Hergispach crops up in the Engers Chronicle from 963. Moreover, the find of a “west German beaker adorned with band”, a replica of which is exhibited at the Landschaftsmuseum Westerwald in Hachenburg, bears witness to a human presence in the area some 4,000 years ago.

In 1343, Emperor Karl IV granted Herschbach town rights, although these were withdrawn 14 years later. At this time, the mediaeval settlement consisted of the moated castle (Arx Hergispach, first documentary mention in 1320), which belonged to the Counts of Isenburg.

In 1371, Herschbach was conquered by Kuno II of Falkenstein, Archbishop of Trier.

Herschbach was mostly spared the Thirty Years' War’s ravages, but the villages of Überherschbach and Dorfborn, even to the Oberherschbach chapel, were destroyed so that their inhabitants would seek and find refuge in the fortified community of Herschbach. Today’s streets, Obertor and Untertor (meaning “Upper Gate” and “Lower Gate”), give some idea of the community's dimensions at that time. The castle within its moat fostered handicrafts.

An especially important era in Herschbach's economic history is said to be the quartzite mining. When the Siershahn-Altenkirchen railway line opened in 1884, it also opened new perspectives on mining the valuable freshwater quartzite (also known as quartzarenitic sandstone, Skršin-type quartzite, Limnic quartzite, or by its German name, Süßwasserquarzit), since there was favourable transport at hand. With the opening of the Kleinbahn Selters–Hachenburg, a narrow-gauge railway whose head office was in Herschbach, began the planned mining in Herschbach's, Rückeroth’s, Freirachdorf’s and Marienrachdorf’s municipal areas in 1900. With the further upswing in the iron industry’s development, “Herschbach quartzite” became one of the most sought-after raw materials for this industry in need of fireproof materials. Quartzite mining was for many years the community's main livelihood. In 1939, 625 workers from Herschbach and the neighbouring communities were employed at the quarries. In the 1950s, quartzite mining was shut down because the waning yields from the quartzite lode made recovery economically unjustifiable. What is left over from the “quartzite boom” is a far-reaching change in the look of the local landscape due to tailing heaps, some of which are today overgrown with low forest. Many abandoned pits are used as fishponds. Unusable land, decayed loading ramps and impassable lands still recall the Herschbach Quartzite Basin. The closure also had great consequences for the narrow-gauge railway, whose tracks were torn up by 1960.