A torque sensor includes: a torsion bar coaxially connecting a first shaft and a second shaft; a multipole magnet; a pair of magnetic yokes; and a magnetic sensor capable of detecting a density of magnetic flux formed by the pair of the magnetic yokes and having an inner magnetosensitive surface facing inward in a radial direction and an outer magnetosensitive surface facing outward in the radial direction when viewed along a central axis of the torsion bar. The torque sensor includes: a magnetic flux guiding member capable of magnetically coupling the magnetic yoke and the outer magnetosensitive surface of the magnetic sensor; and a water blocking portion capable of housing the magnetic sensor and the magnetic flux guiding member to restrict the magnetic sensor from coming into contact with water.