In order to provide a vehicle behavior prediction device and a vehicle behavior prediction method, and a driving assistance device that uses the vehicle behavior prediction device, which enables vehicle behavior to be predicted in a highly accurate manner, a vehicle control device (140) is installed in a vehicle (100). The vehicle control device (140) is provided with a distribution calculation unit (143) and a vehicle behavior prediction unit (145). The distribution calculation unit (143) determines, on the basis of driving condition information that has been collected, probability distributions at occurrence and non-occurrence of deceleration behavior. The vehicle behavior prediction unit (145) determines the relative positional relationships between the traveling speed and acceleration of vehicles ahead with respect to the probability distributions. On the basis of the relative positional relationships that have been determined, the vehicle behavior prediction unit (145) predicts the behavior of a vehicle
