A steering system comprising: a rod member to which a steering member is connected directly or indirectly; a housing having a retaining hole for retaining the rod member such that the rod member is movable in an axial direction, the housing having a clamping slit extending through a circumferential wall of the housing in a radial direction and elongated in the axial direction and including a first clamp-receiving portion and a second clamp-receiving portion both projecting in the radial direction so as to sandwich the clamping slit between the first clamp-receiving portion and the second clamp-receiving portion, the first clamp-receiving portion having a first through hole extending through the first clamp-receiving portion along a first axis that intersects the radial direction, and the second clamp-receiving portion having a second through hole extending through the second clamp-receiving portion along a second axis that intersects the radial direction; and a clamping member configured to clamp the housing so as to reduce a diameter of a part in the axial direction of the retaining hole to lock a position of the rod member, the clamping member including a fixed cam, a clamping shaft, a rotary cam, and a clamping lever, the rotary cam being configured to relatively move away from or toward the fixed cam as the rotary cam rotates relative to the fixed cam, and the clamping lever being connected to the rotary cam, characterized in, that the steering system comprises the fixed cam being fitted in the first clamp-receiving portion from an outer side of the first clamp-receiving portion, the fixed cam having a third through hole extending through the fixed cam coaxially with the first axis, the clamping shaft being inserted through the first through hole, the second through hole, and the third through hole, wherein the third through hole has a small diameter portion at a first portion close to the rotary cam and a large diameter portion having a diameter larger than a diameter of the small diameter portion at a second portion away from the rotary cam. a rod member to which a steering member is connected directly or indirectly; a housing having a retaining hole for retaining the rod member such that the rod member is movable in an axial direction, the housing having a clamping slit extending through a circumferential wall of the housing in a radial direction and elongated in the axial direction and including a first clamp-receiving portion and a second clamp-receiving portion both projecting in the radial direction so as to sandwich the clamping slit between the first clamp-receiving portion and the second clamp-receiving portion, the first clamp-receiving portion having a first through hole extending through the first clamp-receiving portion along a first axis that intersects the radial direction, and the second clamp-receiving portion having a second through hole extending through the second clamp-receiving portion along a second axis that intersects the radial direction; and the first clamp-receiving portion having a first through hole extending through the first clamp-receiving portion along a first axis that intersects the radial direction, and the second clamp-receiving portion having a second through hole extending through the second clamp-receiving portion along a second axis that intersects the radial direction; and a clamping member configured to clamp the housing so as to reduce a diameter of a part in the axial direction of the retaining hole to lock a position of the rod member, the clamping member including a fixed cam, a clamping shaft, a rotary cam, and a clamping lever, the rotary cam being configured to relatively move away from or toward the fixed cam as the rotary cam rotates relative to the fixed cam, and the clamping lever being connected to the rotary cam, characterized in, that the steering system comprises the fixed cam being fitted in the first clamp-receiving portion from an outer side of the first clamp-receiving portion, the fixed cam having a third through hole extending through the fixed cam coaxially with the first axis, the clamping shaft being inserted through the first through hole, the second through hole, and the third through hole, wherein the third through hole has a small diameter portion at a first portion close to the rotary cam and a large diameter portion having a diameter larger than a diameter of the small diameter portion at a second portion away from the rotary cam. the clamping lever being connected to the rotary cam, characterized in, that the steering system comprises the fixed cam being fitted in the first clamp-receiving portion from an outer side of the first clamp-receiving portion, the fixed cam having a third through hole extending through the fixed cam coaxially with the first axis, the clamping shaft being inserted through the first through hole, the second through hole, and the third through hole, wherein the third through hole has a small diameter portion at a first portion close to the rotary cam and a large diameter portion having a diameter larger than a diameter of the small diameter portion at a second portion away from the rotary cam.