A selectable one-way clutch includes: a pocket plate including accommodating recess portions; a notch plate including engaging recess portions; a plate-shaped engaging piece; and a selector plate configured to switch between: a state in which the engaging piece rises toward the notch plate; and a state in which the engaging piece is accommodated in the accommodating recess portion. The notch plate includes a plane portion including a first inclined surface, and the first inclined surface provides the engaging piece with force in a direction into which the engaging piece is urged away from the notch plate, when the notch plate is rotated in an engaging direction into which the engaging piece rising toward the notch plate is engaged with the engaging recess portion, and one end portion of the engaging piece rises toward the notch plate and comes in contact with the plane portion.