British gardener at the Royal Botanic Gardens, Kew, who went on to become a botanical collector in East Asia in 1861. He succeeded the Kew collector G. Wilford, being for some time attached to the surveying vessel Swallow before making extensive collections along the Manchurian coast. He then travelled to Korea and Japan, and was invited to the island of Formosa (Taiwan), then little known to western botanists, by the consul there. He visited and collected in Penang on his way to the island.

While on Formosa Oldham began to suffer particularly ill health, with his heart disease being exacerbated by repeated fevers. In light of this he was forced to return to mainland China for medical attention. His weakened condition was such that he succumbed to dysentery, however, and died in November 1864 at Amoy, where he was buried, far from his birthplace of Macclesfield, England. In all he had amassed about 14,000 plants, including many species new to science, and a number of taxa were named in his honour.

Sources:
D. Oliver, 1867, "Notes upon a few of the plants collected, chiefly near Nagasaki, Japan, and in the islands of the Korean Archipelago, in the years 1862-1863, by Mr. Richard Oldham", Journal of the Linnean Society. Botany., 9: 163-170
B. Seemann, 1866, Journal of Botany, British and Foreign, 4: 239-240
E. Bretschneider, 1898, History of European Botanical Discoveries in China, 2: 682-684.