Lieutenant General Georgios Kostidis was born in 1965 in Kastoria. He was admitted to the Hellenic Military Academy (Evelpidon) in 1983 and graduated in 1987 as Armour Second Lieutenant.
He has attended all Armour Schools and courses, as well as the Army War College and the Hellenic National Defence College. He has been awarded all decorations, medals, and commendations provided for his rank. He holds a Masters Degree in Management of Operational Planning from Nottingham Trent University. He speaks English fluently.
During his career, he has served in Armour Units and, as a Commander, he has served in the 289th Medium Tank Company (Samothrace), the 6th Medium Tank Battalion (Vyronia), the 212th Medium Tank Battalion (Lagos), and as Commander of ΝΑΤΟ Operational Mentor and Liaison Team (Afghanistan).
He has served as staff officer in ISAF-HQ Operations in Afghanistan, 3rd Staff Office Director of the 7th Mechanised Brigade, Operations Staff Officer of the South Eastern Europe Brigade (SEEBRIG), J7 Section Chief NRDC-GR, Operational Planning Chair Director in the Supreme Joint War College, Deputy Commander of the 34th Mechanised Brigade and Director of the Operations Directorate of the Hellenic First Army.
As a General Officer (Brigadier General), he was promoted in 2017 and assigned as Commander of ELDYK/3/1 DEM.
In 2019, he was promoted to Major General and assigned as Commanding General of the Service Support Division. In March 2020, he was assigned as Deputy Commander of D Army Corps. On 09 March 2021, he was assigned as Commandant of the Hellenic Military Academy (Evelpidon).
On 08 March 2022, he was promoted to Lieutenant General and assigned as Commanding General of the Higher Army Support Military Command.
He is married with two sons.