Löwenstein-Wertheim was a county of the Holy Roman Empire, part of the Franconian Circle. It was formed from the counties of Löwenstein (based in the town of Löwenstein) and Wertheim (based in the town of Wertheim am Main) and from 1488 until 1806 ruled by the House of Löwenstein-Wertheim who are morganatic descendants (and the most senior line) of the Palatinate branch of the House of Wittelsbach.
The county of Löwenstein belonged to a branch of the family of the counts of Calw before 1281, when it was purchased by the German king Rudolph I of Habsburg, who presented it to his natural son Albert. In 1441 Henry, one of Albert's descendants, sold it to the Frederick I, Count Palatine of the Rhine, head of the Palatine branch of the house of Wittelsbach, and later it served as a portion for Louis (1494-1524), a son of the elector by a morganatic marriage, who became a count of the Empire in 1494. Louis obtained Löwenstein in Suabia and received from Emperor Maximilian I the 2title of Count of Löwenstein.
The family lost Löwenstein to Ulrich, Duke of Württemberg, but Louis III, Count of Löwenstein, through his marriage to Anna, heiress of the Count of Wertheim, obtained that territory. Louis III left two sons: Christopher Louis, a Lutheran, and John Dietrich, who remained a Catholic, so the family was divided in two: Löwenstein-Wertheim-Freudenberg, a Lutheran branch, and Löwenstein-Wertheim-Rosenberg, a Catholic one. The heads of the two branches, into which the older and Protestant line was afterwards divided, were made princes by the king of Bavaria in 1812 and by the king of Württemberg in 1813; the head of the younger, or Roman Catholic line, was made a prince of the Empire in 1711.
With the dissolution of the German Empire in 1806, the county was disbanded and its territory was split among Bavaria, Baden, Württemberg, and Hesse. Under the protocol of Frankfurt on 20 July 1819 all the family lands were mediatised. The area of the county of Löwenstein was about 140 square kilometres (53 sq mi).