Al Shabab supporters chanted “Messi” – Ronaldo’s long-term rival Lionel Messi – after Sunday’s 3-2 defeat in Riyadh.
Portugal captain Ronaldo, 39, cupped his hand to his ear and made a gesture to the fans.
He has also been fined 30,000 Saudi Riyals (£6,300) by the Saudi Arabian Football Federation (SAFF).
The SAFF disciplinary and ethics committee said Ronaldo cannot appeal against the decision.
Ronaldo opened the scoring from the penalty spot, but Al-Shabab twice came from behind before Talisca scored an 87th-minute winner.
Ronaldo joined Al-Nassr on a free transfer from Manchester United in December 2022 for reportedly the biggest football salary in history.
He has scored 20 goals in 22 league games this season for Al-Nassr, who are second in the table behind Al-Hilal.