Gotha is the fifth-largest city in Thuringia, Germany, 20 kilometres (12 miles) west of Erfurt and 25 km (16 miles) east of Eisenach with a population of 44,000. The city is the capital of the district of Gotha and was also a residence of the Ernestine Wettins from 1640 until the end of monarchy in Germany in 1918. The House of Saxe-Coburg and Gotha originating here spawned many European rulers, including the royal houses of the United Kingdom, Belgium, Portugal (until 1910) and Bulgaria (until 1946).

In the Middle Ages, Gotha was a rich trading town on the trade route Via Regia and between 1650 and 1850, Gotha saw a cultural heyday as a centre of sciences and arts, fostered by the dukes of Saxe-Gotha. The first duke, Ernest the Pious was famous for his wise rule. In the 18th century, the Almanach de Gotha was first published in the city. The cartographer Justus Perthes and the encyclopedist Joseph Meyer made Gotha a leading centre of German publishing around 1800. In the early 19th century, Gotha was a birthplace of the German insurance business. The SPD was founded in Gotha in 1875 by merging two predecessors. In that period Gotha became an industrial centre, with companies such as the Gothaer Waggonfabrik, a producer of trams and later aeroplanes.

The main sights of Gotha are the early-modern Friedenstein Castle, one of the largest Renaissance Baroque castles in Germany, the medieval city centre and the Gründerzeit buildings of 19th-century commercial boom.

Gotha lies in the southern part of the Thuringian Basin in a flat and agricultural landscape.

The city centre of Gotha has two medieval parts: the old town around Hauptmarkt and the new town around Neumarkt. Both were walled until 1810, when the city walls were broken down and a boulevard was laid out in their place. Early-modern suburbiums were established to the south-west (around Dreikronengasse), to the west (around Große Fahnenstraße) and to the east (around Mohrenberg). The later 19th century brought larger growth in all directions. Especially the axis between the main station and the city centre received a representative development in capital-city style. Due to Gotha's function as a ducal residence, most buildings built between 1870 and 1914 were generous in size and many mansions were built. Only some outer districts show the typical German working-class tenements (e.g. around Oststraße and Seebergstraße). The largest Plattenbau settlement of Gotha was established at the western periphery during the late GDR period. In the 1980s, large areas of the western old town were demolished and replaced by small-scale Plattenbau houses. After 1990, many buildings were thoroughly refurbished after having fallen into dereliction during GDR times. Nevertheless, a relatively large share of ruined historic buildings remains characteristic for Gotha (in comparison to neighbouring cities like Eisenach, Erfurt or Weimar), especially within the historic new town and the 19th century belt around the city centre. The government sometimes failed to conserve historic buildings, for example the Volkshaus zum Mohren was demolished in 2007, as was the Winterpalais in 2011 (although the latter has now being reconstructed externally). The Orangerie (Gotha) was saved in 2006, and the Prinzenpalais was restored in 2017 although the adjacent Kavaliershaus was demolished.