 On 24 March 2015, Apostolos Giannou was selected for the Greek National Team for the upcoming UEFA Euro 2016 qualifying match against Hungary.On 5 November 2015, Apostolos Giannou was selected for the Greek National Team for the upcoming friendly matches against Luxembourg and Turkey.On 17 November he made his debut with the Greek national team as a late substitute for Kostas Mitroglou in a 0–0 away draw against Turkey.