John McClellan (1810 – 14 May 1881) was a chemist and industrialist who established one of the first chemical factories in Widnes, Lancashire, England.

He started in business in Liverpool as a drysalter and in 1847 described himself as a merchant, borax manufacturer and ashes refiner.

[2] McClellan was a member of the Widnes Local Board from its inception in 1865 and in 1869 became its chairman.

[2] McClellan married Mary Gaskell, the daughter of a Liverpool cotton broker, in 1844.

Sarah Jane, their eldest daughter, married Henry Brunner, John Hutchinson's chief chemist.