[8] On 22 March 2015 after a remarkable season with the club, Giannis Gianniotas became the 1st player of Asteras Tripolis that was called to play for the Greece national team.

[9] On 23 March 2015, Gianotas alleged to have verbally agreed to Greek champions Olympiacos and seems that Fortuna Düsseldorf which has the player's rights contents to this transfer.

[11] On 17 June, Olympiacos officially announced the transfer of Giannis Gianniotas from Fortuna Düsseldorf, adding another high-caliber Greek talent to their squad.

[13] He made his debut on 10 January 2016, starting the match and playing for 65 minutes in APOEL's 2–1 away victory against Aris Limassol for the Cypriot First Division.

[19] On 16 February 2017, he scored APOEL's second goal one minute before the end, in his team's 3–2 defeat from Athletic Bilbao at San Mamés, for the first leg of the UEFA Europa League round of 32.

[20] One week later, he scored again from the penalty spot, as APOEL beat Athletic Bilbao 2–0 at home and advanced to the last 16 of the UEFA Europa League for the first time in their history.

[24] According to reports from Spain, Real Valladolid after Gianniotas solid performances with the club want to make the loan move of right winger from Olympiacos permanent in the summer.

[27] On 31 October 2018, Alef calmly slid the ball into the left corner after collecting Stratos Svarnas’ accurate pass and Gianniotas’ scored his first goal with the club, to double AEK’s lead in a 4–0 away Greek Cup win.

On 1 September 2016, he scored the winner in Greece's friendly 2–1 away win against Netherlands, pouncing on a rebound that Dutch keeper Jeroen Zoet let spill into a dangerous area.

It remains to be seen what action FIFA or UEFA will take against Bosnia, but on the video evidence, which clearly shows Gianniotas attacking first with a kick and then the punch from Stéphane Gilli which did the damage knocking out a tooth, both associations could be sanctioned.