An optical angle detection apparatus includes a light source section, a sensor section disposed separately from the light source section through a space, a timing controller, and a calculation processing section. The light source section includes a plurality of LEDs and a plurality of first polarizing plates whose polarizing directions differ from each other by 45.degree. in correspondence with the LEDs. The sensor section includes a lens and a two-dimensional PSD. The timing controller sequentially and periodically turns on the plurality of LEDs. The calculation processing section calculates the angle of the light source section relative to the sensor section around an axis determined by the light source section and the inclination angles of the sensor section in two axial directions with respect to the optical axis of the light source section on the basis of an output from the two-dimensional PSD which changes in accordance with the amount of light incident from the light source section onto the sensor section and the coordinates of an incident spot.