A protective cover protects a connector coupling portion which is an electrical connection between an on-vehicle sensor to be mounted on a vehicle body component and a wiring. This protective cover includes a protection portion and a fixing portion. The protection portion covers the connector coupling portion at which a sensor-side connector which is provided on the on-vehicle sensor side and which extends in an extending direction is coupled to a wiring-side connector which is provided on the wiring side and which is to be coupled to the sensor-side connector while moving relatively with respect to the sensor-side connector in a coupling direction opposite to the extending direction. The fixing portion is integrally provided with the protection portion so as to be fixed on the on-vehicle sensor side.