A getting-on/off determination apparatus determines rider's getting-on/off for an inverted two-wheel vehicle that travels while maintaining the inverted state. The getting-on/off determination apparatus includes an optical fiber laid in a step portion that a rider gets on/off, a light emitting unit that emits detection light and is connected to one end of the optical fiber, a light receiving unit that receives the detection light emitted from the light emitting unit and is connected to another end of the optical fiber, at least one transmitted light varying portion that varies an amount of transmitted light of the detection light passing through the optical fiber in conjunction with a vertical displacement of the step portion that occurs when the rider gets on/off the inverted two-wheel vehicle, and a determination unit that determines getting-on/off of the rider based on an amount of the detection light received by the light receiving unit.