James Duncan (1804–1861) was a Scottish naturalist.
- with James Wilson Entomologia Edinensis: Or A Description and History of the Insects Found in Edinburgh (1834)
- in William Jardine's The Naturalist’s Library. Entomology, 7 volumes. (Year unknown)
- Introduction to Entomology.: Comprehending a General View of the Metamorphoses, William Home Lizars, Samuel Highley, W. Curry, Junr. & Co. 662 pages. (1840).
- with William Jardine.Bees: Comprehending the uses and economical management of the honey-bee of Britain and other countries, together with the known wild species. Edinburgh London, W.H. Lizars; Henry G. Bohn. 602 pages. (1859).
James Duncan's papers on Diptera appeared in the Magazine of Zoology and Botany ( 1, ii: 145-61; iv: 359-68; v: 453-6)