The 32-year-old Canadian actor was unable to attend the premiere on Wednesday of director Nicolas Winding Refn's film Only God Forgives.
Gosling stars in the Bangkok noir about a boxing club owner pressured by his mother to his avenge his brother's murder.
At a press conference on Wednesday, Cannes director Thierry Fremaux read a letter from Gosling apologising for his absence. The actor is currently in Detroit shooting his directorial debut, How to Catch a Monster.
"Can't believe I'm not In Cannes," Gosling wrote.
Absence a blow to the festival
"I was hoping to come but I'm on week three shooting my film in Detroit. Miss you all. Nicolas, my friend, we really are the same persons in different dimensions. I'm sending you good vibrations."
His absence is a blow to the festival, which depends on top stars like Gosling to walk its red carpet and draw the world's media attention to the annual French Riviera extravaganza.
Fremaux said he was sad that Gosling couldn't make it.
"He is not with us physically, but as he stated, his thoughts are with us," said Fremaux.
Only God Forgives was screened for the media early on Wednesday at Cannes, where it drew mixed reviews for its extreme violence and nightmarish Greek tragedy. Refn, who also directed Gosling in 2011's Drive, said he understood Gosling needing to stay with his production.
"I would never even do it if I was in his situation," said Refn. "One thing is being an actor. When you're directing, it's another arena.
"But I speak to him every day on the phone. In a way, he is here."
Watch the Only God Forgives trailer here: