A steering system comprising: a restricted member that is restrained from being displaced together with a steering wheel during tilt adjustment; a movable member that is displaced together with the steering wheel during tilt adjustment; a fastening mechanism that fastens the movable member and the restricted member together along a fastening direction in response to a rotational operation of an operating lever; a stationary tooth row provided in the restricted member; and a movable tooth row provided in the movable member, and engageable with the stationary tooth row, wherein the movable tooth row includes a first movable tooth and a second movable tooth; the first movable tooth has a first tooth surface and a second tooth surface, which are inclined in opposite directions, and a rounded portion, which serves as a tooth tip that connects the first tooth surface and the second tooth surface to each other; the second movable tooth has a first tooth surface and a second tooth surface, which are inclined in opposite directions, and a rounded portion, which serves as a tooth tip that connects the first tooth surface and the second tooth surface of the second movable tooth to each other; and the inclination of the tooth surfaces (93, 94, 96, 97) of the first and second movable teeth (91, 92), relative to the radius line of the movable tooth row, are equal to each other, characterized in that a tooth depth of the first movable tooth is made greater than a tooth depth of the second movable tooth by setting a first curvature radius of the rounded portion of the first movable tooth smaller than a second curvature radius of the rounded portion of the second movable tooth. a restricted member that is restrained from being displaced together with a steering wheel during tilt adjustment; a movable member that is displaced together with the steering wheel during tilt adjustment; a fastening mechanism that fastens the movable member and the restricted member together along a fastening direction in response to a rotational operation of an operating lever; a stationary tooth row provided in the restricted member; and a movable tooth row provided in the movable member, and engageable with the stationary tooth row, wherein the movable tooth row includes a first movable tooth and a second movable tooth; the first movable tooth has a first tooth surface and a second tooth surface, which are inclined in opposite directions, and a rounded portion, which serves as a tooth tip that connects the first tooth surface and the second tooth surface to each other; the second movable tooth has a first tooth surface and a second tooth surface, which are inclined in opposite directions, and a rounded portion, which serves as a tooth tip that connects the first tooth surface and the second tooth surface of the second movable tooth to each other; and the inclination of the tooth surfaces (93, 94, 96, 97) of the first and second movable teeth (91, 92), relative to the radius line of the movable tooth row, are equal to each other, characterized in that a tooth depth of the first movable tooth is made greater than a tooth depth of the second movable tooth by setting a first curvature radius of the rounded portion of the first movable tooth smaller than a second curvature radius of the rounded portion of the second movable tooth.