A suspension system for a vehicle includes a roll control device, which includes an actuator, for controlling roll, and a control device including a target control value determining portion determining target control value of the actuator and an operation control portion controlling the actuator on the basis of the target control value. The target control value determining portion determines the target control value on the basis of estimated lateral acceleration when degree of actual lateral acceleration is smaller than a predetermined threshold, and by weighting the estimated lateral acceleration to gradually decrease from one to zero and by weighting the actual lateral acceleration to gradually increase from zero to one when the actual lateral acceleration is greater than the predetermined threshold, the target control value determining portion determines the target control value of the actuator on the basis of the sum of the weighted estimated lateral acceleration and the weighted actual lateral acceleration.