The 37-year-old actress said on Tuesday's episode of Watch What Happens Live that she's on good terms with Simpson following their misunderstanding this month.
Portman spoke out after a fan asked if she has talked to Simpson offline since their miscommunication.
"No, only [online]," the star responded. "I have only respect and good feelings for her."
"There's no need for beef between women," she said. "We're all in the same society and living with the same pressures. We're allies."
Simpson had called out Portman on Instagram after Portman remarked about an old magazine cover featuring Simpson in a bikini. Portman said she was "confused" by the image and Simpson's message about her virginity.
"@Natalieportman - 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 Dec. 5.
"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," she said.
Portman apologized to Simpson and clarified her remarks in the comments of the post.
"@jessicasimpson Thank you for your words. I completely agree with you that a woman should be allowed to dress however she likes and behave however she likes and not be judged," the actress said.
"I only meant to say I was confused - as a girl coming of age in the public eye around the same time - by the media's mixed messages about how girls and women were supposed to behave," she explained. "I didn't mean to shame you and I'm sorry for any hurt my words may have caused."
Portman most recently starred in the movie Vox Lux, which opened in theaters Dec. 7. She will next appear in The Death and Life of John F. Donovan with Jacob Tremblay.