A collision avoidance device includes a collision avoidance executor, a determiner, and a collision avoidance controller, for example. The collision avoidance executor can execute a collision avoidance function for a vehicle to avoid collision with an object to be avoided. The determiner determines, based on an operation of an accelerator pedal by a driver, whether the driver has an intention of acceleration. The collision avoidance controller inhibits execution of the collision avoidance function when the driver is determined to have the intention of acceleration. The determiner further determines, based on the operation of the accelerator pedal, whether the driver has an intention of cancelation of the collision avoidance function. The collision avoidance controller ends the execution of the collision avoidance function when the driver is determined to have the intention of cancelation during the execution of the collision avoidance function.