Mason, John Monck (1725–1809), politician and literary commentator, was born in Dublin, eldest son of Robert Mason, soldier, of Mason Brook, Co. Galway, and Sarah Mason (née Monck), author of the popular Poems by Miranda. Educated privately by Mr Young, he entered TCD (1741), where he graduated BA (1746) and MA (1761). After studying at the King's Inns, he was called to the bar (1752), but soon abandoned the law for politics. Entering the house of commons, he was MP for Blessington, Co. Wicklow (1761–8, 1769–76), and St Canice, Co. Kilkenny (1776–1800). Although not a good speaker on entering parliament, he soon developed an effective and eloquent style and was regarded as ‘rather an able debater than a fair reasoner’ (quoted in HIP, v, 202). He initially won some notice for his opposition stances. His favourite issue was a bill to allow catholics to invest in land mortgages, which he proposed unsuccessfully in 1761, 1762, and 1773. To secure his support for government he was appointed commissioner of barracks and public works (1771), and he then replaced John Foster (qv) as a commissioner of revenue (1772–93). His new support for government alienated many of his former opposition colleagues, especially Lord Charlemont (qv), and his hostility to the free trade campaign of 1779 created many enemies: he became so unpopular that for a time he was afraid to return home. He voted against an Irish regency and with the administration in 1789, and against catholic emancipation in 1795. He was made a privy councillor (1783) and chairman of the committee of accounts, and, as a reward for his support of the act of union (1800), he was granted an annual pension of £300. His nickname, for reasons unknown, was ‘Monck Moonshine’.
A literary commentator of mixed repute, in 1779 he published a four-volume edition of the dramatic works of Philip Massinger. This, he claimed, was completely free from errors, but it proved to be quite the opposite. Turning to the works of William Shakespeare, he prepared Comments of the late edition of Shakespeare's plays (1785), and a further analysis that was published in 1807. He also published a commentary on the plays of Beaumont and Fletcher in 1798. He was elected a member of the Dublin Society (1768) and the RIA (1792). He died 2 April 1809 in Dublin.
He married (11 July 1766) Catherine Mitchell, from Glasnevin, Co. Dublin; they had no children. His nephew was the historian William Monck Mason (qv).