Mendenitsa (Greek: Μενδενίτσα), in the Middle Ages known as Mountonitsa (Μουντονίτσα) and Bodonitsa or Vodonitsa (Βοδονίτσα), is a village in Phthiotis, Greece. It is part of the municipal unit of Molos.
The village is located on the northern slopes of Mount Kallidromon, some 6 km southeast of Thermopylae. The early history of the settlement is obscure; it was likely a Slavic settlement of the middle Byzantine period.
Mendenitsa only appears in the sources during the late Middle Ages, as the seat of the Marquisate of Bodonitsa, a Frankish Crusader state established in 1204 to guard the strategic pass of Thermopylae, that connected northern and southern Greece. Its first ruler, Guido Pallavicini, also built the castle, possibly located on the site of an ancient acropolis, often identified with that of the city of Pharygai. The Chronicle of the Morea reports that the original fief was granted by Boniface of Montferrat, King of Thessalonica, but following the recovery of Thessaly by the Greek Despotate of Epirus, it was soon cut off from Thessalonica, and formed indeed the northernmost march of the Latin states of southern Greece. By the middle of the century, the marquess became a vassal of the Principality of Achaea, and ranked among the twelve foremost barons of that realm.