A golf club head comprises a face portion having a front face defining the club face and a rear face facing a hollow, wherein the face portion is provided on the rear face with an upper rib, a lower rib, a toe-side groove and a heel-side groove which extend radially from a thickest central region, so as to form a toe-side upper region, a toe-side lower region, a heel-side upper region and a heel-side lower region. The thickness distribution of the face portion satisfies the following magnitude relations: (Central region>=upper rib); (central region>=Lower rib); (upper rib>Toe-side upper region>Toe-side groove); (Lower rib>Toe-side lower region>Toe-side groove); (upper rib>Heel-side upper region>Heel-side groove); and (Lower rib>Heel-side lower region>Heel-side groove).