The Australian actor starred as Nellie LaRoy alongside Brad Pitt in the comedy drama film, released in 2022, and Robbie still can't understand why it wasn't a big hit with cinemagoers.
"I am still saying (why didn't it prove popular). I love it," the 34-year-old said during an appearance on the Talking Pictures podcast.
Robbie, who is from regional Queensland, ultimately hopes the movie will develop cult-classic status.
"I know I am biased because I am very close to the project and I obviously believe in it, but I still can't figure out why people hated it," she said.
"I wonder if in 20 years people are going to be like, 'Wait, Babylon didn't do well at the time?' Like when you hear that Shawshank Redemption was a failure at the time and you're like, 'How is that possible?'"
Margot Robbie has taken some time out from acting after having a baby with husband Tom Ackerley. (EPA PHOTO)
Meanwhile, Robbie is said to be currently enjoying the challenges of motherhood.
The star and her husband Tom Ackerley recently welcomed their first child, a boy whose name and birth date have yet to be revealed, and the loved-up couple are relishing the challenges of parenthood.
"They have been hanging out in (Los Angeles) as a family. Tom's mom has been visiting from England," a source told People magazine.
Robbie plans to return to work in 2025 but for the time being, the actor is keen to spend some quality time with her baby and her husband.
"Margot has several projects lined up next year. She wants to rest now and spend time with the baby. She's enjoying motherhood," the insider said.