Abstract: A ball joint is disclosed. The ball joint comprises: a ball stud including a ball and a stud; a bearing coupled to the ball stud so as to surround the outer peripheral surface of the ball; a ball casing for accommodating the ball and the bearing therein; and an insert filled inside the ball casing, and coupled to the ball casing and the bearing, and further includes rotation-preventing wings extending outwards in the radial direction from the outer surface of the bearing, and coming into contact with the inner surface of the ball casing so as to prevent the bearing from rotating when an external pressure is applied to the bearing.