The "Oz: The Great and Powerful" actress, who is expecting her first child with boyfriend Ashton Kutcher, stopped by the show wearing a white sleeveless dress, reported Ace Showbiz.
"Congratulations, so you hid it for a while, you got away with it for a long time," the host Ellen DeGeneres said.
"I did. I managed to hide it for a very long time," Kunis replied.
She did not want to reveal the sex of the unborn baby, but said "yes" when the host asked whether she and Kutcher had picked a name.
"He assumed that I was gonna have goofy cravings, so he stocked our secondary fridge with weird food. Just like pickles, and sauerkraut, or like anchovies, and ice creams... Just in case at one point during this pregnancy I'd be like I really want something," she said.
"And it happened last week, I was like oh my God, I need a pickle. Like it was just the weirdest thing. Like I needed this pickle and he was like hold on a second and disappeared in the backyard and came back with the most amazing dill pickle of all time," she added.