Charles Noyes Forbes (1883 - 1920) was an American botanist.
Forbes was born in Boylston, Massachusetts on 24 September 1883. When he was at the University of California he worked as a cadet for the emergency service during the 1906 San Francisco earthquake. From 1908 to 1920 he was curator of Botany at the Bernice P. Bishop Museum in Honolulu. During that time he made several expeditions to the bogs, cliffs, mountain ranges and valleys in the Hawaiian islands and collected many plant taxa which were new to science. In 1919 he was the first botanist who explored the flora of the Haleakalā bog in eastern Maui. Among the plants which were scientifically described by Forbes are several which are either very rare or even extinct, including Cyanea parvifolia, Hibiscadelphus bombycinus and Clermontia tuberculata. Species such as Pipturus forbesii and Cheirodendron forbesii were named in his honour. Charles Noyes Forbes died at age 36 on 10 August 1920 in Honolulu.