On February 19, 1945, the 28th Marines landed at Green Beach during the battle of Iwo Jima. The regiment sustained severe casualties and the advance on Mount Suribachi was delayed. Williams moved to the front line and directed his Marines in the assault, ultimately resulting in the capture of Mount Suribachi by February 23. Williams and the 28th Marines continued fighting until the island was secured on March 26. For his actions throughout the battle, Williams was awarded the Silver Star.