Toure will be working alongside his former Manchester City manager Roberto Mancini, who took charge in August.
Toure recently left a similar role at Belgium side Standard Liege.
The 40-year-old has also held assistant coaching roles at Ukrainian side Olimpik Donetsk and Russian outfit Akhmat Grozny and Tottenham Hotspurs in recent seasons.
On Friday, Toure tweeted: "When Roberto asked if I would join him in Saudi Arabia for this important project, while it was difficult to step away from Standard Liege, I knew it was the right move for me. I have always looked up to Roberto - so to work with him and learn from him is a perfect fit.
"Being part of football in Saudi Arabia gives me an opportunity to work in a Muslim country for the first time in my career. This is something I have always wanted to do. I cannot wait to get out on the field and start coaching at an exciting time for the game in Saudi Arabia!
"Although it was short, positive memories of my time at Standard Liege will never leave me - I now have a special bond with this great club. The fans are incredible. Their passion for their club is unbelievable. They welcomed me into their club and I am thankful to them for this."
Toure, who is a four-time African footballer of the year, spent eight seasons with Manchester City where he won three Premier League titles, one FA Cup and two League Cups.
Toure also played for AS Monaco and Barcelona, where he won the 2009 UEFA Champions League and two La Liga titles.
He was a member of the Ivory Coast national team that beat Ghana on penalties to win the 2015 African Cup of Nations.
