A collision avoidance assist device that performs an assist for avoiding a collision between a vehicle and an object includes an object detection unit that detects the object around the vehicle, a time calculation unit that calculates a time to collision between the vehicle and the object based on the detection result of the object detection unit, and an assist control unit that suppresses a release of a braking for avoidance assist as the time to collision decreases when an execution of the collision avoidance assist is controlled based on the time to collision.