2 years old would have done it with ease. My daughter wouldn't have been able to until age 4. It depends on the kid, but in general those unable to sit in a theater seat without getting up and running around during the movie shouldn't go to the movie, IMO. It's not fair to the kid to expect them to sit there and isn't fair to the other people that have to be distracted by a yelling or wandering toddler. If one parent needs to spend 2 hours at the park while the other parent and kids go to the movie, so be it.