A steering device includes a rotation central portion having a rotation axis Ax of the steering device and a steering unit connected to the rotation central portion. The direction in which the rotation axis of the rotation central portion extends is an axial direction. One of directions perpendicular to the axial direction is a radial direction. A direction perpendicular to the axial direction and the radial direction is a width direction. The steering unit protrudes from the rotation central portion in the radial direction in plan view of the steering device in the axial direction. A maximum width of the steering unit in the width direction is less than or equal to a maximum width of the rotation central portion in the width direction.