Panathinaikos BC OPAP announces the one-year agreement with Giannis Athinaiou.
Athinaiou was born in May 27, 1988), he is 1.94 m (6 ft 4 1⁄2 in) tall and he can play at both the point guard and shooting guard positions.
He played from a young age in Poseidonas, a club in Psychiko, Athens, Greece, before he started his pro career.
He first played professionally with the Greek clubs Ilysiakos, Panionios, and KAOD. In the summer of 2009, he signed a 4-year contract with Panionios. He joined the Greek League club Aris, in 2013.
He joined the Italian League club Olimpia Milano, in 2014. After that he signed with the Greek EuroLeague team Olympiacos, in 2015. With Olympiacos, he won the Greek League championship in 2016. He returned to Aris, for the 2017–18 season.
On July 29, 2018, he signed a two-year contract with Aris' arch-rivals, PAOK. In 2019, he joined the French League club Fos Provence.
Athinaiou was a member of the Greek university national team. He played at the 2007 World University Games. He has also been a member of the senior Greek national basketball team. He played with Greece at the 2016 Turin FIBA World Olympic Qualifying Tournament. He also played at the 2019 FIBA World Cup qualification.