Kunis, 31, was the among the first guests on James Corden's "The Late Late Show".
When he asked, "Either you're married or you're not." She replied saying, "Maybe."
Corden then demanded to show her wedding finger, where there was a ring. He announced, "They are married, look." Kunis looked on a little red-faced.
During the interview, Corden also asked her about motherhood after giving birth to baby Wyatt in October. Kunis simply answered "Maybe."
The actress called Kutcher, 37, "an amazing father".