The House of Saxe-Coburg and Gotha is a European royal house. It takes its name from its oldest domain, the Ernestine duchy of Saxe-Coburg and Gotha, and its members later sat on the thrones of Belgium, Bulgaria, Portugal, and the United Kingdom and its dominions.

Saxe-Coburg and Gotha, or Saxe-Coburg-Gotha, was an Ernestine duchy in Thuringia ruled by a branch of the House of Wettin, consisting of territories in the present-day states of Thuringia and Bavaria in Germany. It lasted from 1826 to 1918. In November 1918, Charles Edward, Duke of Saxe-Coburg and Gotha, was forced to abdicate. In 1920, the northern part of the duchy was merged with six other Thuringian free states to form the Free State of Thuringia: Saxe-Weimar-Eisenach, Saxe-Altenburg and Saxe-Meiningen, Schwarzburg-Rudolstadt and Schwarzburg-Sondershausen, as well as the People's State of Reuss. The southern part of the duchy, as southernmost of the Thuringian states, was the only one which, after a referendum, became part of the Free State of Bavaria.