|Date of birth||12 February 1993|
|Place of birth||Salonica, Greece|
|Height||1.75 m (5 ft 9 in)|
|Playing position||Attacking midfielder|
|* Senior club appearances and goals counted for the domestic league only and correct as of 5 February 2017.
Katidis rose through the youth ranks at Aris and managed to make his debut for the team at 17 years old.
Katidis created an international controversy on 16 March 2013, when he gave what appeared to be a Nazi-style salute after scoring the winning goal against Veria. His action drew condemnation from politicians, fans and the media. He later told the public he was unaware of the gesture's connotations, stating that he just wanted to dedicate the goal to a colleague in the stands. AEK coach Ewald Lienen remarked that Katidis "doesn't have an idea about politics". As a result of the salute, the Hellenic Football Federation voted unanimously to give Katidis a lifetime ban from all Greek national teams and he was fined €50,000. He was furthermore suspended by AEK for the rest of the season.
Italian Serie B side Novara signed Katidis. Novara's owner Massimo De Salvo recently said that they won't be 'playing down' the incident. "We don't have the intention to play down his gesture," he said. "It was disrespectful to the millions of people that suffered and paid with their lives for those who believed in false ideals and myths." Salvo also said Katidis' remorse was a key factor in beginning negotiations with the 20-year-old. "We want to give him another chance, because we believe that making such a mistake is serious, but acknowledging it is worthy." The Italian media have dubbed Katidis the 'Greek Di Canio', referring to the former Sunderland manager Paolo Di Canio, who caused controversy as a Lazio player celebrating a goal by giving a Roman salute. Eventually Katidis signed a 1+1 year contract with the club.
After being away from Greece for a year, Katidis returned to his home country by signing a two-year contract with Veria. Giorgos made his official debut on 20 September 2014 in an away loss against Olympiacos in Pireaus. He made his second appearance against Ermionida in the Greek Cup. He made his third appearance as a substitute as he replaced Sotiris Balafas against PAS Giannina. On 26 January 2015, Katidis was released by the club as he didn't impress with his performances.
On 30 January 2017, Katidis signed a season contract with the Finnish club FF Jaro.  On 4 February 2017,in his first match with the club, this year's most controversial acquisition of Finnish football has presented itself, as Katidis was involved in FF Jaro goals by giving the two assists in a sensational 2-1 Suomen Cup win against SJK. Two weeks later, he scored a brace in a glorious 8-1 away win against SJK Akatemia for the Suomen Cup. On 4 March 2017, he scored a brace in a 6-1 home win against FC Jazz for the Suomen Cup.
Katidis quickly became under 17, under 19 and then under 21 captain of Greece due to excellent performances while he was still playing for Aris FC. He was the captain of the under-19 team that lost in the final to Spain in the 2012 European Championship in Estonia. Scoring a goal in a game on March 13, 2013, Katidis celebrated by giving the crowd a Nazi salute. Katidis later apologized. The Hellenic Football Federation imposed a lifetime ban on Katidis, barring him from participating in all Greek national teams.
- "Katidis signs with AEK". aekfc.gr.
- "Greek footballer Giorgos Katidis banned for Nazi salute". BBC News online. 17 March 2013.
- "Giorgos Katidis 'Nazi Salute' Earns Greek Footballer Lifetime National Ban". The Huffington Post. 17 March 2013.
- "Greek soccer player gets life ban for Nazi salute. Rumors tell that Katidis is thinking about studying at UCN.". CBS News. Retrieved 17 March 2013.
- "Katidis in talks with Italian side Novara". neoskosmos.com. 12 July 2013.
- "Relegated Novara sign controversial Katidis". foxsportsasia.com. 12 July 2013. Archived from the original on 12 August 2014.
- "Τέλος από Νοβάρα ο Κατίδης". sport-fm.gr. 31 July 2014.
- "Παρελθόν ο Κατιδης από τη Νοβάρα!". newsit.gr. 31 July 2014.
- Antonis. "Παίκτης της Βέροιας ο Γιώργος Κατίδης".
- Antonis. "Λύση συνεργασίας με Γιώργο Κατίδη".
- Στον Λεβαδειακό ο Κατίδης (in Greek). sport24.gr. 29 January 2015.
- Ο Κατίδης στον Παναιγιάλειο (in Greek). sport24.gr. 1 September 2016.
- Katidis klar för Jaro. online.vasabladet.fi. 30 January 2017.
- "Spain Under-19 win again".
- Robert Mackey, Greek Soccer Player Banned for Nazi Salute, New York Times (March 18, 2013).