Henry Ogg Forbes (30 January 1851 – 27 October 1932) was a Scottish explorer, ornithologist, and botanist.
Forbes was the son of Rev. Alexander Forbes, M.A., and Mary née Ogg, his wife. and was born at Drumblade, Huntly, Aberdeenshire. He was educated at Aberdeen Grammar School, the University of Aberdeen and the University of Edinburgh, he was primarily active in the Moluccas and New Guinea, he served as director of the Canterbury Museum in New Zealand between 1890–1893, and eventually moved to Liverpool, England, where he served as a consulting director of museums there until his death. He is mentioned in A Short History of Nearly Everything by Bill Bryson.
The zoologist William Alexander Forbes, who died on an expedition to West Africa in 1883, was H. O. Forbes's friend and fellow-classmate at the University of Edinburgh; the book A Naturalist's Wanderings in the Eastern Archipelago is dedicated to him.
The standard author abbreviation H.O.Forbes is used to indicate this individual as the author when citing a botanical name.