The vehicle motion control device of the invention utilizes that the detected lateral acceleration Gyd based upon the output from the lateral acceleration sensor takes a value obtained by adding a value corresponding to the roll angle to the actual lateral acceleration based upon the centrifugal force exerted on the vehicle and that the actual lateral acceleration can accurately be calculated and estimated, as the estimated lateral acceleration Gye, based upon the output from the yaw rate sensor, whereby this device judges that there is a tendency in which an excessive roll angle occurs on the vehicle to thereby execute the predetermined roll-over preventing control, when the increasing speed of the detected lateral acceleration Gyd exceeds the first predetermined value and the increasing speed of the estimated lateral acceleration Gye becomes smaller than the second predetermined value (