“Why would you do that when your name is your brand,” one person wrote on social media.
“Changing your … name as a well-known celebrity feels like a bad business decision,” someone else said.
“Barbie would never take a man’s surname,” another social media user added.
Other fans chimed in, saying they would still call her Margot Robbie.
“Her mama named her Margot Robbie, I’m calling her Margot Robbie,” one person wrote.
Many fans speculated on the reason behind the change, with some saying a lot of people wait a long time because they put off filling out the paperwork.
Other fans pointed to the fact that the couple has recently welcomed their first child and the actress may have chosen to now share a last name with her son.
The star and her producer husband, who have been married since 2016, welcomed a baby boy in October 2024.