An optical position detecting device includes a plurality of light source sections which emits detection light, a light detection section which receives the detection light reflected by a target object located in an emitting space of the detection light, a light source driving section which turns on some light source sections among the plurality of light source sections in a first period and turns on, in a second period, light source sections different from the light source sections turned on in the first period, and a position detecting section which detects the position of the target object on the basis of a light-receiving result of the light detection section in the first period and the second period. Each of the light source sections includes a plurality of light-emitting elements arrayed in a direction intersecting the direction of the optical axis of the detection light.