Born on 16 June 1845, he was the eldest son of Thomas Selby of Whitley and Wimbush Hall, Essex, by his wife Elizabeth, youngest daughter and coheiress of Ralph Foster of Holderness, Yorkshire.
[1] In 1867 Selby became a junior clerk in the Public Record Office, where he ultimately became superintendent of the search-room.
In 1883, with his friend James Greenstreet, he founded the Pipe Roll Society, of which he was director-in-chief, and honorary treasurer for the rest of his life.
[1] Selby cut his own throat while suffering from typhoid fever, dying at his residence, 9 Clyde Street, Redcliffe Gardens, London S.W., on 3 August 1889.
He was a contributor on literary subjects to The Athenæum, The Academy, The Antiquary, Antiquarian Magazine, and other periodicals.