The design of an active seat suspension for a mid-class passenger vehicle based on the given set of requirements is considered a combination of four subsystems; the carrier, the actuator, the spring, and the damper. The design of the former two is considered through the 10 and 16 concepts for each, respectively. Two overall designs are proposed for further development. One based on a dual Scott-Russell mechanism and one based on Sarrus mechanism. The first one is evaluated to have high stiffness, the second to be more cost-effective. The detailed design of the first concept is presented.