كتب : Omar AbdelAziz
The German replaces Italian tactician Alberto Bigon, who brought Essam Al-Hadari from Ahli last season.
Stielike is aiming to challenge top teams in the Swiss Super League and enhance Sion's position after they finished seventh in 2007-2008.
"The objective is to close the gap on the big teams in the championship," said the former Germany star.
Stielike led Ivory Coast to the 2008 African Cup of Nations, but was unable to manage the team during the competition in Ghana due to the illness of his son, who eventually died.