In October 1854 he entered Magdalene College, Cambridge, where in the following year he was elected to a Milner close scholarship.
In 1860 he gained the Crosse scholarship, and in the same year was ordained deacon and priest in the diocese of Ely.
The following year he was appointed, on the nomination of Trinity Hall, to the vicarage (non-stipendiary) of St Edward's, Cambridge.
On the death of Fenton John Anthony Hort in 1892, he was chosen to succeed him as Lady Margaret professor of divinity.
[2] Lumby was one of the founders of the Early English Text Society, and edited for it King Horn (1866), Ratis Raving (1867), and other pieces.
To the Pitt Press series he contributed editions of Francis Bacon's Henry VII (1876), Venerabilis Bædæ Historiæ … Libri iii.
Mayor, 1878), Thomas More's Utopia, in Ralph Robynson's English translation (1879), More's History of Richard III (1883), and Abraham Cowley's Essays (1887).