A selectable one-way clutch includes: a shaft; an actuator configured to cause the shaft to perform a rectilinear motion in a shaft direction; and an arm including an operation portion configured to receive force in the shaft direction from the shaft. The shaft includes a first flange and a second flange. An engaged state and a released state the selectable one-way clutch are switched by an operation of the arm by the rectilinear motion of the shaft, in an assembled state of the shaft and the arm in which the operation portion is arranged between the first flange and the second flange. The first flange is provided with a cut portion in an outer peripheral edge of the first shaft. The shaft has a structure in which the first flange does not face the operation portion in the shaft direction by the cut portion of the first flange.