Seth Bemis (January 23, 1775 - April 4, 1851) was an American entrepreneur, active along the Charles River in the early Industrial Revolution. It is claimed that he was the first to manufacture cotton duck cloth. He was also father to attorney George Bemis. Sometime before 1810, Bemis introduced machinery for grinding and cutting glass and for polishing lights for lighthouses, as well as for insertion in the decks of vessels and binnacle lights, under a patent granted in 1809 to Captain Winslow Lewis (who was also his selling agent for cotton duck).