Grand Ma[i]gne ("Great Maina", in ) or Vieux Ma[i]gne ("Old Maina", in ) was a Frankish castle in the Mani Peninsula, Greece. It was built, according to the Chronicle of the Morea, ca. 1248–1250 AD by William II Villehardouin, the Prince of Achaea. He was captured by the Byzantines in 1259 at the Battle of Pelagonia, and had to give up the castle as part of his ransom.