Thanasis Antetokounmpo’s journey in basketball started early. He played for the Greek minors in 2008 and was also part of the Filathlitikos junior teams. He later played as a semi-professional for Greek third division during the 2011-12 Season. Finally in 2012, he was roped in to play for the senior men’s team of Filathlitikos of the Greek second division.
At the 2012–13 Greek 2nd Division season with Filathlitikos, he scored an average of 12.2 points, 4.9 rebounds, 1.0 assists, 1.1 steals and 1.0 blocks per game.
He was originally declared for the 2013 NBA draft but withdrew from it on June 17, 2013 along with 17 other players. Same year, he was selected to play for the Greek All Star Game as a special participant and in the slam dunk contest.
On November 1, 2013, Thanasis Antetokounmpo was the ninth overall pick in the 2013 NBA Development League Draft. He was selected by Delaware 87ers. He performed to his full potential at the matches averaging 12.0 points, 4.3 rebounds, 2.1 assists, 1.2 steals and 1.3 blocks in 50 games.
On May 1, 2014, he was named to the 2014 NBA D-League All-Defensive third team. Thanasis’s performance at the 2013 NBA matches helped him become the 51st pick at the 2014 NBA draft. Selected by New York Knicks, he played for the team at the NBA Summer League where he averaged 3.0 points and 1.8 rebounds in five games.
On November 2014, Thanasis was acquired by the Westchester Knicks. In the 47 games that he played for Westchester, he averaged 13.9 points, 6.2 rebounds, 1.7 assists, 1.7 steals, and 1.7 blocks per game.
Thanasis Antetokounmpo returned to New York Knicks for the 2015 season of the NBA Summer League. He represented the team at the summer league, playing five matches in which he averaged with 6.4 points, 1.8 rebounds and 1.2 blocks.
From August 2015 to February 2016, he switched his position between New York Knicks and Westchester Knicks, playing for both the teams alternatively.
On August 8, 2016, Thanasis Antetokounmpo signed a contract with MoraBanc Andorra of the Liga ACB. His role in the team was an instrumental one as Andorra hadn’t qualified to the ACB playoffs since 22 years. His contribution in the team was vital in breaking the record. His average of 12.7 points and 4.7 rebounds helped the team reach the playoff before finally being eliminated by Real Madrid.
Thanasis Antetokounmpo’s Nigerian legacy and heritage earned him a spot at the senior Nigerian men’s national team for the 2016 Rio Olympics. However, a Greek by heart, he declined the offer, and instead chose to play with the senior Greek national team. Later, he was selected to the country’s 12-man roster for the 2016 Turin FIBA World Olympic Qualifying Tournament.
On July 11, 2017, Antetokounmpo signed a two-year deal with Panathinaikos.