An in-vehicle lighting device for alerting a driver driving a vehicle to an obstacle present in a vicinity of the vehicle, which obstructs driving of the vehicle. The in-vehicle lighting device includes: a light emitter that is installed in an interior side of a pillar in a front part of the vehicle and that emits light of different chromatic colors; a controller connected to the light emitter; and a detector that is connected to the controller and detects the obstacle present in the vicinity of the vehicle. When the detector detects the obstacle present in the vicinity of the vehicle, the controller causes the light emitter to emit light having a color according to a characteristic of the obstacle detected.