Al-Nassr have dropped points in two of their last four matches which has seen them overhauled by Al-Ittihad at the top of the league.
Garcia joined Al Nassr last summer following stints at the likes of AS Roma, Olympique Marseille and Olympique Lyon.
The 59-year-old led Lille to the French Ligue 1 title in the 2010/2011 season.
Garcia was reportedly criticised for his tactics by Ronaldo after Al-Nassr drew goalless with Al-Feiha over the weekend.
Croatian manager Dinko Jelicic has been promoted from his role as u-19 boss to oversee Al-Nassr's final seven matches of the season.
The Riyadh-based club said: "Al Nassr can announce that head coach Rudi Garcia has left the club by mutual agreement.
"The board and everyone at Al Nassr would like to thank Rudi and his staff for their dedicated work during the past 8 months.
"We can announce that our U19 coach, Mr Dinko Jelicic will be the new head coach for the first team. Good luck, Mr Dinko."
Al-Nassr are next in action against Al-Hilal on April 18.
