Williams grew up in a working-class family in a state house in the Auckland suburb of Mount Albert.[14] In describing his struggling family background, Williams later stated that the "driving factor" in his pursuit of playing professional rugby league was to "get my mum a house."[15] He attended Owairaka Primary School,[16] Wesley Intermediate and Mount Albert Grammar School. As a child, he has been described as being a "small, skinny white kid"[17] who was "painfully shy," as well as "a freakish sporting talent, a competitive sprinter, a champion high jumper and cross country runner and the kid who played footy in teams a couple of age divisions above, to make things fairer."[14] Despite being tipped to have a promising future in athletics, Williams abandoned it when he was about 12 years old.[13] Though his father was an accomplished rugby league player, Williams has said it was his mother who introduced him to the game.