Photographers spotted the 36-year-old actor and Mila Kunis walked through the airport in denim and hoodies. Kunis, 30, sported a large diamond on her ring finger.
Kutcher and Kunis, former That 70s Show co-stars, have yet to publicly confirm Kunis' pregnancy. The Jupiter Ascending star hid any early signs of a baby bump in a loose-fitting dress at CinemaCon on Thursday.
She was seen at a prenatal yoga class in Hollywood last week.