The controversy started when Portman spoke with USA Today about her new movie Vox Lux — which is about an aging pop star — when the actress brought up Simpson and how she viewed the singer when she was younger.
"I remember being a teenager, and there was Jessica Simpson on the cover of a magazine saying 'I'm a virgin' while wearing a bikini, and I was confused," Portman told the outlet. "Like, I don't know what this is trying to tell me as a woman, as a girl."
Simpson has since fired back, sharing a statement directly addressing Portman and her comments.
"I was disappointed this morning when I read that I 'confused' you by wearing a bikini in a published photo taken of me when I was still a virgin in 1999," Simpson wrote in her statement. "As public figures, we both know our image is not totally in our control at all times, and that the industry we work in often tries to define us and box us in."
"However, I was taught to be myself and honor the different ways all women express themselves, which is why I believed then – and I believe now – that being sexy in a bikini and being proud of my body are not synonymous with having sex," she continued.
"I have always embraced being a role model to all women to let them know that they can look however they want, wear whatever they want and have sex or not have sex with whomever they want," Simpson went on to say. "The power lies within us as individuals. I have made it my practice to not shame other women for their choices."
"In this era of Time's Up and all the great work you have done for women, I encourage you to do the same," Simpson's statement concluded.
Many of the singer's social media followers have been cheering her on for her clap back, but some have noted that Portman's comment doesn't necessarily strike them as a jab at Simpson.
"Wait, after reading this entire article, it doesn't seem like Natalie is even hating," one person commented. "She's talking about the industry and her thoughts to that when she was younger."
"Have [you] considered [Natalie Portman] might not have called [you] out but the magazine? That it wasn't [you] but the media that, actually, caused confusion by not thinking about how headlines in combination [with] specific pictures come across? Could've been any example," someone else suggested. "I think she's with [you]."
At this time, Portman does not appear to have replied to Simpson's comments.