The illegitimate son of Dr. William Oldys, chancellor of Lincoln, Oldys lost much of his patrimony in the South Sea Bubble, and moved to Yorkshire where he lived with the Earl of Malton. In 1738 he was appointed secretary to Edward Harley, second earl of Oxford, whose library he catalogued with Samuel Johnson. After the death of his patron Oldys contributed to many scholarly projects, notably the Biographia Britannica (1747-60). In 1751 he was imprisoned for debt; in 1755 he was appointed Norroy king-at-arms by the duke of Norfolk.
1748An Historical Essay on the Life and Writings of Michael Drayton.
1750 ca.[Notes for a Biography of Edmund Spenser.]
1758Some Account of the Life and Writings of Edmund Spenser.
1763Biographia Britannica: Edmund Spenser.
A dissertation upon pamphlets and the undertaking of Phoenix britannicus to revive the most excellent of them. 1731.
Life of Sir Walter Raleigh in Raleigh, History of the World. 2 vols, 1736.
The British librarian. 1737.
The Muses library [Elizabeth Cooper, with Oldys]. 1741.
Memoirs of Mrs Anne Oldfield [attributed to Oldys]. 1741.
The Harleian miscellany: or a collection of scarce, curious and entertaining tracts and pamphlets [ed. Oldys]. 8 vols, 1744-46.
Biographia Britannica [major contributor]. 5 vols, 1747-60.
Some account of the life and writings of Charles Cotton in Izaac Walton, Compleat Angler. 1760.
Diary, ed. J. Yeowell. 1862.