Demetrius (Dimitri; Georgian: დიმიტრი) (c. 1413 – 1453) was the second son of King Alexander I of Georgia by his first wife Dulandukht Orbeliani.

On Vakhtang's death, Demetrius became a de jure king of Georgia but his accession to the throne was precluded by his younger brother George VIII.

Traditional Georgian historiography founded by Prince Vakhushti in the 18th century erroneously makes him a younger brother of George VIII and frequently omits him from the list of the kings of Georgia.

[1] After Alexander I's renouncement of the throne in 1442 in favor of Vakhtang IV, Demetrius remained a co-king with the latter, whereas Alexander's third son, George VIII, was made a co-king appanaged in Kakheti.

Upon the death of Vakhtang IV in 1446, Demetrius III was to become de jure king-regnant of Georgia, but the throne was seized by George VIII, inaugurating a series of conflicts which would eventually lead to the dissolution of the kingdom of Georgia by the close of the 15th century.