Golf club heads with internal and/or external ribs, and thinned regions are described herein. The thinned regions of the golf club heads can be strategically positioned such that club head weight is reduced in certain regions to optimize center of gravity (CG) location; while the internal and/or external ribs prove the structural strength the golf club heads require to withstand impact forces during a game. The discretionary weight saved from the thinned regions can be repositioned elsewhere on the golf club head to further optimize the CG location to benefit the moment of inertia to effect ball spin, speed, distance, and trajectory. Other embodiments and related methods are also disclosed herein.