| Theodosius III თეოდოს III | |
| Succession: | King of Abkhazia |
| Reign: | 975 – 978 |
| Predecessor: | Demetrius III |
| Successor: | Bagrat III |
| House: | Anchabadze |
| House-Type: | Dynasty |
| Religion: | Georgian Orthodox Church |
Theodosius III the Blind (Georgian: თეოდოს III; also known as Theodosius the Sorrowed) was King of the Abkhazians from circa 975 to 978. He was the fourth son of George II of the Anchabadze dynasty. He succeeded his brother Demetrius III, who died without a male heir.
King George II of Abkhazia sent two of his younger sons, Theodosius and Bagrat, to Constantinople to be educated there, so that after his death there would be no dispute during his succession. After his reigning brother Leon III died in 967, a rebel party of Meskhetian, Egrisian and Kartlian nobles encouraged Theodosius to assert his rights against his brother, Demetrius III. Victorious in the ensuing civil war, Demetrius had Theodosius captured and blinded.
Theodosius first took refuge in the Kartli with certain Adarnase, then with David III of Tao where he remained for a while, and finally moved at the court of Kvirke II of Kakheti. Demetrius III managed to convince Theodosius to organize a reconciliation, who agreed to return to Abkhazia with guarantees of personal security confirmed by oaths before the Catholicos and the clergy. The central government was still powerful enough to cope with the local separatism, but not for surmounting the growing structural crisis. The weakness of the government brought about another act of cruelty. Demetrius caught his brother Theodosius in plotting again and makes blind.
It was not until the death of childless Demetrius in 975, when Theodosius was able to ascend the throne. During the short reign of King Theodosius III, the kingdom became engulfed into complete chaos and feudal anarchy combined with the raids by the Kakhetians in Kartli, where the royal power had completely collapsed and a governor, Ioanne Marushis-dze, allied with the Georgian Bagratid prince David III Kuropalates of Tao to install Theodosius's nephew (sister's son) Bagrat as a ruler of Kartli in 975. In 978, through Marushidze's efforts, Gurandukht's weak reigning brother Theodosius III was deposed and Bagrat, now of age, proclaimed King of Abkhazia. Since then Theodosius disappeared from history.