The two have been criticized for failing to take the safety measure in the new 3-D movie "Hannah Montana/Miley Cyrus: Best of Both Worlds Concert Tour."
Pop star and actress Miley Cyrus is enormously popular with young teens.
"We got caught up in the moment of filming, and we made a mistake and forgot to buckle our seatbelts," Billy Ray Cyrus told People.com. "Seatbelt safety is extremely important."
The movie opened at No. 1 with an estimated $29 million at the U.S. box office the first weekend in February and has grossed about $40 million so far.
NASA celebrates Earth Day with #GlobalSelfie
Lytro unveils camera that can focus a photo after shooting it