An optical deflector includes: a light transmitting portion through which a light passes; and a pair of electrodes arranged to oppose to each other with the light transmitting portion interposed therebetween. The light transmitting portion is a transparent ion conductor made of a single crystal or polycrystal. The pair of electrodes apply a predetermined voltage to the light transmitting portion to move ions inside the transparent ion conductor so as to change a traveling direction of the light passing through the light transmitting portion.