The singer was photographed at the event holding her baby boy, who was crying.
The photo was shared on social media and quickly went viral.
In the caption of the photo, Rihanna revealed that her son was crying because he was sad about his unborn sibling not being able to attend the Oscars with them.
Rihanna announced her pregnancy in January 2023 but has not revealed the baby's due date or gender.
The identity of the baby's father has also not been disclosed.
Rihanna has been vocal about her desire to have children in the past, stating in a 2019 interview that she wants to be a mother "more than anything in life."