Beusmans was born in Hampshire and moved with his parents to Cornwall, where the senior Beusmans ran a retail pottery shop.  John helped them in the business and began potting himself in the 1960s. Preparing for a career in ceramics, he studied the art of throwing at Redruth School of Art.  He sold ceramics from his parents' shop, and then set up his own Carn Pottery in 1971 at Nancledra, near Penzance, where there is still an active commercial pottery today.

In 2005 a book about the Carn Pottery and the work of John Michael Beusmans, was published, as referenced below.