The castle of Leuktron (Greek: Λεύκτρον) or Beaufort is a late medieval fortification in the southern Peloponnese.

The fortress was built c. 1249 by the Prince of Achaea, William II Villehardouin, on the eastern shore of the Messenian Gulf, in order to keep at bay the Slavic tribes living on Mount Taygetos. It is located close to the ancient settlement of Leuctra and the modern village of Stoupa, on a large rock rising above the shore, forming a platform some 120 metres (390 ft) long, 50 metres (160 ft) wide, and less than 80 metres (260 ft) high that extends from northeast to southwest. The curtain wall is constructed of irregular-sized stones mixed with brick fragments. Remnants of a square keep and a cistern are still visible in the interior.

• Andrews, Kevin A. (2006). Castles of the Morea. American School of Classical Studies at Athens. ISBN 978-0-87661-406-8.
• Bon, Antoine (1969). La Morée franque. Recherches historiques, topographiques et archéologiques sur la principauté d'Achaïe [The Frankish Morea. Historical, Topographic and Archaeological Studies on the Principality of Achaea] (in French). Paris: De Boccard. OCLC 869621129.
• Setton, Kenneth M. (1976). The Papacy and the Levant (1204–1571), Volume I: The Thirteenth and Fourteenth Centuries. Philadelphia: The American Philosophical Society. ISBN 0-87169-114-0.

36°50′34″N 22°15′54″E / 36.8428°N 22.2650°E / 36.8428; 22.2650