A golf club head having a low-density insert located in a top portion thereof. The insert may be only in the top line of the club head or extend from the heel around the toe. The insert may extend through a hosel and optionally be visible on a heel-side surface. The insert may be mounted on a back surface of a striking face, and may extend a distance down the back surface. The insert may extend into, and provide part of, a golf ball striking face.