A golf club head according to one or more aspects of the present invention may generally include a strike face, a top portion, a bottom portion, a heel portion, a toe portion, and a hosel having a central axis located in a first imaginary vertical plane. A discrete, at least partially curvilinear stiffening element, having generally vertical side surfaces, may be coupled to at least one of the top portion and the bottom portion to improve the dynamic-excitation response of the club head. Preferably, the stiffening element is oriented such that an imaginary horizontal line intersects at least one of the vertical surfaces at at least two points. Additionally, the stiffening element may have at least two inflection points located along a non-linear path characterized by the vertical projection of one of the side surfaces onto at least one of the bottom portion and the top portion of the club head.