John Mills (1717 – 1786 or 1796) was an encyclopedist on the Encyclopédie. He was originally a writer on agricultural matters from England. He proposed and worked on the Encyclopédie with Gottfried Sellius, a native of Gdańsk, who, after being a professor at Halle and Göttingen and residing in the Netherlands, had settled in Paris.
Mills and Sellius originally proposed simply to translate articles from Chambers' Cyclopaedia into French. However, Mills's knowledge of French was inadequate, the publisher André Le Breton was extremely dissatisfied with Mills's work, and Le Breton eventually physically assaulted Mills. Mills took Le Breton to court, but the court decided that Mills's incompetence had warranted the attack. Le Breton replaced Mills with Jean Paul de Gua de Malves, who in turn was later replaced by Denis Diderot.
Soon after the court ruling Mills left for England. In the 1760s he surfaced in London, where he became a well known author on the subject of husbandry. In 1766 he became a member of the Royal Society.