France-born Giovanni Sio played youth football with Nantes, but he was forced to go to Spain to embark on his first stepping stones towards becoming a professional footballer. He joined the reserve side of Read Sociedad and although he played a few games for the senior side in the Spanish Second Division, he was released at the end of the 2008/9 season and joined Swiss club Sion, where he initially played in the youth side before being promoted to the first team. He was soon noticed outside the Swiss borders and German Bundesliga club VfL Wolfsburg signed him on a four-year contract at the beginning of 2012.

After originally seeing regular playing time with the team from the north of Germany, he fell out of favour and was sent on loan, first to Augsburg and then Sochaux. At the start of the 2013/4 season he joined Basel and played an important part as the team enjoyed a successful run in the Champions League – twice beating finalists Chelsea in the group phase before advancing to the quarter-finals of the Europa League. The pacey striker with a hard work rate played youth football for France, but then opted to play for Côte d'Ivoire. Sio, who debuted for the Elephants' in 2013, played in four matches in the 2014 FIFA World Cup™ qualifying campaign.