George Dedas started basketball from the local team of Kilkis and in 1998 he moved to Thessaloniki and the team of MENT. Thereafter, he played for Iraklis while the seasons 2006-2007 and 2007-2009 he played for the Spanish League and the teams of Breogan and Rossalia respectively. The next season he stayed in Spain and played basketball for Caceres Basket.

The season 2010-2011 George returned to the Greek Basketball League and played for the first time at the team of PAOK for which continues to play after a short break the season 2011-2012 when he moved to Rethymno and the local team.

With the Greek National Team he won the 2nd place at the Mediterranean Games in Almeria, Spain (2005).