Leading sports daily Marca called the Portuguese striker's birthday bash after Real's Madrid derby defeat in the league on Saturday "The Party of Discord."
"Pictures of the celebration did not go down well with Real Madrid's captains" Iker Casillas and Sergio Ramos, Marca wrote on Monday.
Ronaldo hosted teammates including second-choice goalkeeper Keylor Navas, defender Pepe, Fabio Coentrao, Luka Modric, Sami Khedira and James Rodriguez, who recently had foot surgery, newspapers reported.
Participants including Colombian singer Kevin Roldan, who was invited to entertain guests at the party, posted photographs on social networks of Ronaldo and various grinning teammates.
A video was leaked of an upbeat Ronaldo, singing alongside Roldan.
"The online social networks were on fire with fierce criticism from fans," reported Madrid sports newspaper AS.
Disgruntled Twitter users even generated a special hashtag, #lafiestadeladeshonra, or "party of disgrace".
"It was a trending topic all day from 12:00 pm," said Madrid sports newspaper AS.
Cristiano's agent Jorge Mendes told Cadena SER radio station on Sunday he himself was "very annoyed" by the photographs.
"When there is an event that is totally private and then you see someone is leaking pictures of it, clearly you get annoyed," Mendes said.
The agent said the player was "gutted at the defeat" — a claim echoed by other figures close to Ronaldo, including Chelsea and former Real manager Jose Mourinho.
"People spent the first two hours of the party encouraging him because he was sad about the defeat," Mendes said.
Barcelona newspaper Sport reported that some Real players who missed the party were going to "demand an explanation from the Portuguese player and his fellow partygoers".
Real Madrid are currently top of the Spanish league on 54 points, but Saturday's loss left them just a point ahead of their fierce rivals Barcelona.
Current champions Atlético are three points behind in third place.