Madonna's comment on a picture posted by the account"catholicnewsagency" - the private Catholic media network CNA/EWTN - has provoked more than 1,500 responses so far.
The singer reacted critically to a photo of Pope Leo XIV with the caption: "Pope Leo XIV: My priority is the Gospel, not solving the world's problems".
According to CNA/EWTN, this abbreviated quote refers to an extract from the Pope's most recent interview.
Pope Leo said there: "I do not see my main task as solving the world's problems. I don't see my role that way at all, although I think that the Church has a voice, a message that must continue to be preached, that must be spoken out loud."
"Making the world a better place"
Madonna wrote on Instagram on Friday: "The point of teaching and learning the Gospel is to inspire people to love one another and make the world a better place. Not just with words, but with actions, and that's exactly what Jesus did. I'm really disappointed in this."
Madonna's followers commented in support and posted pictures of the singer. Other CNA followers explained that if Madonna was disappointed, it was all ok - "go on lovely Pope!!!"
Madonna last appealed to Pope Leo XIV in August to do everything in his power to save children in the Gaza war. "Please travel to Gaza and bring your light to the children there before it is too late."
He added: "Humanitarian access must be opened wide before it is too late." The Pope is "the only one of us who cannot be denied access".