Frederick Barnard Fetherstonhaugh /ˈfænʃɔː/, QC (June 2, 1863 – July 6, 1945) was a Canadian patent lawyer and agent who founded the patent agency Fetherstonhaugh & Co. He was a prominent citizen of Toronto, Ontario and was widely recognized for his expertise in patent law. He was also the owner of one of the first electric cars in Canada.