John Mason Loomis (January 5, 1825 – August 2, 1900) was a nineteenth-century American businessman and lumber tycoon from Chicago who was known for developing the city of Ludington, Michigan. He was involved with the Pere Marquette Lumber Company, which also operated salt distilleries that in turn influenced the salt industry of northern Michigan. The village of Pere Marquette benefited from these local industries and developed into the city Ludington.