The actress, 50, turned heads in her hip-hugging white satin slip dress from Christian Dior by John Galliano.
Aniston took home the award for outstanding performance by a female actor in a drama series in Apple TV's ''The Morning Show.''
Aniston confidently walked the red carpet in the silky dress and her appearance quickly lit up Twitter when eagle-eyed fans pointed out the outfit left very little to the imagination.
"Jennifer Aniston wearing a white dress with no bra while Brad Pitt is in the room is the mood I’m going for in 2020," one person tweeted.
"I wonder if Jennifer Aniston knows how visible everything is in that dress," wrote another.
"can see jennifer aniston’s nipples thru her dress not sure how to feel," one person noted.
"I know way too much about Jennifer Aniston's breasts thanks to her dress."
Later in the night, Aniston and Pitt were snapped backstage looking happy as ever as they reunited to talk about their respective SAG Award wins. In one photo of their backstage chat, both are smiling as Aniston speaks to her ex while touching his arms. Another photo shows him holding onto her wrist as she walks away with her hand on his chest.
Brad and Jen married in 2000 but split in 2005 after he got together with his “Mr. and Mrs. Smith” co-star Angelina Jolie. Pitt and Jolie married in 2014 but split in 2016. In 2019, their divorce was finalized.