Henry Owen was educated at Ruthin school and Jesus College, Oxford; he matriculated in April 1736 at 19, graduated in 1739 and again (in medicine) in 1746, and took his M.D. in 1753. He was ordained in 1746, and was curate and physician in Gloucestershire for three years, after which he gave up his medical practice on account of ill-health. He became chaplain to a gentleman, who in 1752, presented him to the rectory of Terling, Essex; he was also curate at Stoke Newington. He was elected F.R.S. in 1753. In 1760 he was appointed rector of S. Olave's, Hart Street, near the Tower (and therefore the Navy Office); and in 1775, while he was chaplain to bishop Barrington of Llandaff, the bishop gave him the additional living of Edmonton. He d. at Edmonton, 14 Oct. 1795. For his children and descendants, see Powys Fadog, loc. cit.

There is no doubt at all of Owen's scholarship — in mathematics, in classics, in Hebrew and Greek Biblical criticism. But he also interested himself in Welsh antiquities, and in the Welsh manuscripts belonging to William Jones (1675?-1749) (q.v.). True, Sir John Lloyd was convinced that the attribution to Owen of the 1775 History of Anglesea, including an essay on Owain Glyn Dŵr attributed to Thomas Ellis of Dolgelley (these attributions are made in Llyfryddiaeth y Cymry), is erroneous — the History, says Sir John, was by John Thomas (1736-1769) (q.v.) of Beaumaris, and the essay was the work of Robert Vaughan (q.v.) of Hengwrt. Still, Owen certainly brought out the 2nd ed. of Mona Antiqua Restaurata, by Henry Rowlands (1655-1723) (q.v.). He was a prominent Cymmrodor, and acted as reviser of the papers sent up to be read before the society. There is much talk of him in the Morris Letters. He was a neighbour and friend of Richard Morris's — not that this prevented Richard from satirical references to his marriage to a woman very much younger than himself (and a bishop's daughter), or from telling his brothers that Owen was ‘a miserly devil, who changed his maidservants almost every week.’ All three brothers pestered Owen for advice in their frequent and varied illnesses. Owen himself was a sickly man — 'a thin man.’ Other friends of his were Silvanus Bevan (q.v.) and John Evans (1702-1782) (q.v.).