Disclosed is an apparatus for controlling tint of a display panel provided on a vehicle window to adjust light transmittance depending on ambient light conditions, thereby overcoming difficulties in securing a clear view, such as glare caused by sunlight or high-beam headlamps of a vehicle in the opposite direction lane during driving. The apparatus includes: a display panel film attached to a window glass of the vehicle, and having an adjustable tint; an operation unit setting the tint of the display panel film; a detection sensor unit quantifying a change in an external environment into data; and a control unit adjusting the tint of the display panel film according to a preset program by using the data received from the detection sensor unit.