There is no inventor credited with inventing the toilet plunger. There are varied musings about the actual invention of the toilet plunger, but there are no concrete facts about its inventor.
The first patent filed with the U.S. Patent and Trademark Office for a toilet plunger was in 1987 by Emanuel Torti. Some credit for a plunger system is given to Samuel Prosser for his invention of the plunger toilet closet in 1777 which made use of a plunger to release waste and water. Urban legend attributes the invention to Jeffrey Gunderson in 1932, although others maintain that the plunger dates back as far as the 1850s.