Except for New Hampshire, all states and the District of Columbia require adult front-seat occupants of motor vehicles to use seat belts. Adult rear-seat passengers are also covered by the laws in 31 states and the District of Columbia. Children are covered by separate laws.

State seat belt laws are divided into two categories: primary and secondary. Primary seat belt laws allow law enforcement officers to stop a motor vehicle and to issue a ticket or citation to a driver or passenger for not wearing a seat belt without any other traffic offense having occurred. Secondary seat belt laws only allow law enforcement officers to issue a ticket or citation for not wearing a seat belt when there has been another traffic offense by an occupant of the vehicle for which the occupant may be issued a ticket or citation.

In South Dakota, seat belt use is mandated by state law. South Dakota has a primary seat belt law for front-seat occupants, which means that law enforcement officers can stop and ticket a driver or front-seat passenger solely for not wearing a seat belt. The law requires all drivers and passengers in the front seat to wear a properly adjusted and fastened seat belt. For rear-seat adult passengers, South Dakota does not have a seat belt requirement, so they are not legally required to buckle up. However, South Dakota does have specific laws regarding child passenger safety. These laws require that children are properly restrained in a car seat or booster seat appropriate for their age, height, and weight. The child passenger safety laws are more stringent and provide specific guidelines that must be followed to ensure the safety of child occupants in a vehicle.