Passive safety comprises all measures designed to offer protection in the event of an accident. Examples include the NECK-PRO head restraint (standard equipment for front seats): when the sensor detects an impact from the rear, it thrusts the head restraint 44 mm forwards and 30 mm upwards in a matter of a microseconds to reduce the gap between it and the occupant's head.

The S-Class is also equipped with nine airbags, including a kneebag and two windowbags covering virtually the entire side window area. Sidebags are also installed as standard in the rear to protect passengers on the rear seat bench. Extensive development has been invested in the trigger sensors controlling sidebag and windowbag deployment. Other key features include the air pressure sensors, which help the conventional crash sensors to trigger the sidebags and windowbags faster and more precisely.

Air pressure sensors in the S-Class detect air pressure changes in the door caused by deformation. They then trigger the restraint systems within a matter of milliseconds. This can further reduce the danger of injury to vehicle occupants.