Triantafyllos Kordogiannis was a Greek career officer. In 1912 he was appointed Military Commander of the town of Nigrita in Macedonia, which had been conquered by Greece in the First Balkan War. He was replaced in January 1913 due to increasing tensions with neighbouring Bulgaria. Fighting with Bulgarian troops, he was seriously injured in his knee. Kordogiannis was transferred to the town of Serres for treatment and never saw combat again. In 1914, he was awarded the Silver Cross of the Order of the Savior. Four years later, he was put on permanent leave due to a sickness (or injury) as a major in the infantry but was later promoted to lieutenant-colonel to improve his salary.
Kordogiannis won silver with the Greek sabre team at the 1906 Intercalated Games in Athens after having been defeated by the German team. At the time, he was just 16-years-old. In 1912, he was again selected for the individual sabre event but did not start.