|Ecumenical Patriarch of Constantinople|
|Church||Church of Constantinople|
|Appointed||29 August 1702|
|Term ended||25 October 1707|
Smyrna ( İzmir)
|Died||25 October 1707|
|Previous post||Metropolitan of Chalcedon|
Gabriel was born in the town of Smyrna (now İzmir) to parents coming from the island of Andros and in 1688 he became Metropolitan of Chalcedon.  He was elected Patriarch of Constantinople on 29 August 1702 and reigned till his death.  His reign had no particular troubles and was serene.
In 1704 Gabriel formally condemned the edition of the New Testament into Modern Greek translated by Seraphim of Mytilene and edited in London in 1703 by the English Society for the Propagation of the Gospel in Foreign Parts. :269 On 5 March 1705 he issued an order forbidding the Greek students to study in London due to improper behaviours.  In 1706 he issued a letter to condemning the Latin doctrines. :257
He also intervened in the affairs of the autonomous Church of Cyprus, deposing Germanos II of Cyprus after complaints of the local population. The Melkite Metropolitan of Aleppo Athanasius Dabbas was so elected in Istanbul as regent ( proedros) Archbishop of Cyprus at end 1705. In February 1707, after Athanasius' return to Constantinople, Gabriel censored as non-canonical the consecration of the new Archbishop Jacob II, who nevertheless reigned until 1718. 
With regards to his birth-town Smyrna, in 1706 he founded there a school where the scholar Adamantios Rysios taught.  Gabriel died in Constantinople on 25 October 1707 and was buried at the monastery of Kamariotissa on the island of Halki. 
- Kiminas, Demetrius (2009). The Ecumenical Patriarchate. Wildside Press LLC. p. 40,181. ISBN 978-1-4344-5876-6.
- Moustakas Konstantinos. "Gabriel III of Constantinople". Encyclopaedia of the Hellenic World, Asia Minor. Archived from the original on 12 March 2012. Retrieved 24 June 2011.
- Doll, Peter (2006). Anglicanism and Orthodoxy. Frankfurt Am Main: Lang. p. 257,269,437. ISBN 978-3-03910-580-9.
- Runciman, Steven (1985). The Great Church in captivity. Cambridge University Press. p. 303. ISBN 978-0-521-31310-0.
- Hill, George (2010). A History of Cyprus, vol 4. City: Cambridge Univ Pr. pp. 342–3. ISBN 978-1-108-02065-7.
- "Γαβριὴλ Γ´". Ecumenical Patriarchate. Retrieved 23 June 2011.(in Greek)