William King, also known as Bill King, is a Scottish writer of a number of science fiction and fantasy books, most notably in Games Workshop's Warhammer and Warhammer 40,000 series, published by Games Workshop's fiction arm Black Library.

Warhammer Fantasy is a fictional fantasy universe created by Games Workshop and used in many of its games, including the table top wargame Warhammer Fantasy Battle, the Warhammer Fantasy Roleplay (WFRP) pen-and-paper role-playing game, and a number of video games: the MMORPG Warhammer Online: Age of Reckoning, the strategy games Total War: Warhammer, Total War: Warhammer II and Total War: Warhammer III and the two first-person shooter games in the Warhammer Vermintide series, Warhammer: End Times - Vermintide and Warhammer: Vermintide 2, among many others.