An in-vehicle wireless charging system including a warning unit that generates a warning notifying a user that a vehicle is in a situation inappropriate for the user to leave the vehicle when a door opens under a situation inappropriate for the user to leave the vehicle. The warning unit is constantly supplied with power. A wireless charging device supplies power to a charged device set at a predetermined charge location in the vehicle. A first switch detects whether or not the charged device is set at the charge location. The warning unit generates the warning notifying the user that the vehicle is in a situation inappropriate for the user to leave the vehicle when the door opens under a situation in which the charged device has been determined from the detection of the first switch as being set at the charge location.