A collision mitigation apparatus includes an object detecting section for detecting a collision object present in front of an own vehicle on which the collision mitigation apparatus is mounted, a drive assisting section that performs drive assist for avoiding a collision between the collision object detected by the object detecting section and the own vehicle, or mitigate damage to the own vehicle due to the collision, a reliability determining section for determining reliability of detection result of the object detecting section, and a timing setting section for setting start timing to start the drive assist by the drive assisting section in accordance with the reliability determined by the reliability determining section.