John Henry Leech (5 December 1862 – 29 December 1900) was an English entomologist who specialised in Lepidoptera and Coleoptera. His collections from China, Japan, and Kashmir are in the Natural History Museum, London. These also contain insects from Morocco, the Canary Islands, and Madeira. He wrote British Pyralides (1886) and Butterflies from China, Japan and Corea, three volumes (1892–1894). He was a fellow of the Linnean Society and of the Entomological Society of London, a member of the Société entomologique de France, and of the (Entomologischen Verein zu Berlin).