Portraits are often confused with those of his brother Benjamin
(1706-57), physician and playwright, with whom he collaborated in writing The Suspicious Husband
, 1747. 
Benjamin pre-deceased both his father and his brother John. A portrait by Hayman described as Benjamin Hoadly and his wife, in the Wellcome Institute of the History of Medicine, exhibited 'Francis Hayman', 1960 (11), shows a man with features not unlike the John Hoadly of NPG 2106
. The lady is shown holding a mask which might be a reference to the brothers' interest in the theatre (as in Hayman's painting of Mrs Pritchard and Garrick); the sitter is perhaps his second wife Anne Armstrong of whom little is known. 
A head by Hogarth in the Clumber sale, 4 June 1937, lot 37, now in the Smith Collection, Northampton, Massachusetts, signed and dated 1741, is catalogued as Benjamin Hoadly, the father, but might be John; whereas lot 38, now Art Gallery of New South Wales, Sydney, also by Hogarth and catalogued as Pelham might well represent Benjamin, his brother. The short half length in Lord Malmesbury's collection inscribed on the back The Revd. Dr. Hoadly
is another possible candidate for John. Portraits by Hogarth agreeing in features with Benjamin, the son, are the head and shoulders in the National Gallery of Ireland, signed and dated 1740, and the whole length in the Fitzwilliam; both were in the W. Benoni White sale, Christie's, 23-24 May 1879. Walpole noted at the Society of Artists, 1761 (47) 'Three portraits' by Hogarth, 'Dr Hoadley etc.'. 
A group by Hogarth, formerly in the collection of Matthew Raper, FRS, FSA, of Wimpole Street, shows Benjamin 
with the family of his first wife Elizabeth Betts.
1) Cp also the account of Hoadly portraits, R. B. Beckett, Hogarth
, 1949, pp 52-53.
2) Referred to as the daughter of General John Armstrong, Gentleman's Magazine
, Part II, 1788, p 836.
3) 'Notes by Horace Walpole ... on the Exhibitions of The Society of Artists and the Free Society of Artists, 1760-1791 ...', edited H. Gatty, Walpole Society, XXVII, 1939, p 68.
4) J. Nichols and G. Steevens, The Genuine Works of William Hogarth
, 1808-17, III, p 182.This extended catalogue entry is from the out-of-print National Portrait Gallery collection catalogue: John Kerslake,
Early Georgian Portraits, Her Majesty's Stationery Office, 1977, and is as published then. For the most up-to-date details on individual Collection works, we recommend reading the information provided in the Search the Collection results on this website in parallel with this text.