An optical sensor includes a light emitter to emit light, a light receiver to receive the light emitted from the light emitter, a first resin body that covers the light emitter and the light receiver to transmit the light emitted from the light emitter to emit the light outside, and a second resin body that seals the light emitter and the light receiver, in which the second resin body is included inside the first resin body, and the second resin body is harder than the first resin body.