Robert Johnston (1783–1839) was a plantation owner in Jamaica and an investor in the London & Greenwich Railway.
He was the son of Alexander Johnston (died 1786), owner of the Murphy's Penn estate in Saint Ann Parish, Jamaica, and his wife Elizabeth Collett Gilbert.
[3] Later Johnston owned the Harmony Hill estate in Jamaica, for which he received compensation.
[4] Johnston was one of the founders of the Southampton and London Railway and Dock Company, in 1831, with George Walter, and Abel Rous Dottin, also from Jamaica and a relation.
[3] Johnston married in 1818 Catherine Cole Taylor, heiress to Harmony Hill.