Robert Leslie Ellis (25 August 1817 – 12 May 1859) was an English polymath, remembered principally as a mathematician and editor of the works of Francis Bacon.

[2] Although he had also entered the Inner Temple in 1838, was called to the bar in 1840, and later helped William Whewell (his eventual brother-in-law via sister 'Fanny')[1] with jurisprudence, Ellis never practised law.

Ellis took on the editing of Francis Bacon's works with two other Trinity fellows, Douglas Denon Heath and James Spedding.

Dramatic deterioration of Ellis's health from 1847 left his work on the general prefaces to Bacon's philosophy unfinished.

[3] Leslie translated Dante, Roman law texts and Danish ballads; a gentle melancholia suffuses the lines of his own poetry which he left in manuscript.