John Horne FLS (1835–1905) was a Scottish botanist.
He served as director of the Botanic Gardens of Pamplemousses, Mauritius.
He worked at Kew in 1859–1860 and at the Botanic Gardens in Mauritius 1861–1891, serving as Director from 1877 onward.
Upon his transfer to Fiji, Arthur Gordon hand-picked a retinue of officials to accompany him, including Horne, who moved to Fiji a year after Gordon, in 1876.
Horne died in Jersey in the Channel Islands on 16 April 1905.