The Cream of Barley Mill is a historic mill in the town of Bowmanville, Municipality of Clarington, Ontario, Canada. Scottish immigrant John MacKay created a new hot cereal product called "cream of barley". In 1884 he bought the preexisting Caledonia Mill, situated on the banks of Soper Creek on the outskirts of the town of Bowmanville, to manufacture his product. The mill was originally built in 1805 by Leonard Soper as a grist mill, and was owned and operated by several others before being bought by McKay. McKay designed and installed new equipment for the milling of barley.