A sun visor includes: a first light-blocking plate having a base attached to a seat width direction inside surface of a head rest of a front seat disposed in a vehicle via a fastener whose axial direction coincides with the seat width direction and selectively assuming a stored state in which the first light-blocking plate lies along the seat up and down direction about the fastener and a use state in which the first light-blocking plate lies along the seat front and rear direction about the fastener; a second light-blocking plate having a base end portion attached to a seat width direction outside surface of the head rest of the front seat via the fastener and selectively assuming the stored state and the use state; and a third light-blocking plate that interconnects in the seat width direction the first light-blocking plate and the second light-blocking plate.