Demetrios Palaiologos or Demetrius Palaeologus (ca.

1407–1470) is an East Roman (Byzantine) prince and Despot.

He rules over Mesembria and Lemnos, before becoming Despot in the Morea in 1449.

He remains co-ruler of the Morea along with his brother Thomas Palaiologos until he surrenders Mistras to the Ottomans in 1460.

He is given lands in Thrace as an appanage by Sultan Mehmed II, which he rules until his disgrace in 1467.

Shortly after, he is allowed to retire to Adrianople with his wife.

He becomes a monk with the monastic name David after the death of his daughter Helena Palaiologina in 1469, and dies in 1470.