A collision mitigation apparatus for mitigating damage to a vehicle at a time of collision, on which the collision mitigation apparatus is mounted, includes an operation control unit that detects a collision object present around the vehicle, makes a comparison between a collision time indicative of a time remaining before collision between the vehicle and the collision object and an operation reference time according to which timing to start control for avoiding collision is set, and causes a collision mitigation device mounted on the vehicle to start operating depending on a result of the comparison. The collision mitigation apparatus further includes a collision probability calculating unit that calculates a collision probability between the vehicle and the collision object, and a reference time setting unit that sets the operation reference time depending on the collision probability.