Ryan, Daniel Frederick (c.1762–1798), loyalist, was the son of Dr Ryan of Wexford and his wife Mary, daughter of William Morton of Ballinaclash, Co. Wexford. He trained as a surgeon under Alexander Cunningham and was subsequently army surgeon in the 103rd Regiment, commanded by Sir Ralph Abercromby (qv). On the reduction of that regiment in 1784 he returned to Dublin, married Catherine Bishopp of Kinsale, Co. Cork, and continued his practice as a surgeon. His uncle by marriage was John Giffard (qv), who in 1793 bought the loyalist paper Faulkner's Dublin Journal, on which Ryan soon began work. He is commonly referred to as the editor of the paper, but he seems rather to have been a contributor. He was an ardent loyalist and joined the yeomanry corps, first entering the Stephen's Green divisional corps and then forming the St Sepulchre's corps, of which he was captain. He also busied himself with assisting the town-major, Henry Charles Sirr (qv), and his deputy John Swan with the execution of their police duties, and was instrumental in the capture of a United Irishman, William Putnam McCabe (qv). His zeal drew the attention of Castlereagh (qv) and the under-secretary, Edward Cooke (qv), who asked him to assist Sirr and Swan on 19 May 1798 in arresting Lord Edward FitzGerald (qv). At Murphy's house in Thomas St., where FitzGerald was hiding, Sirr remained below with eight men while Swan and Ryan proceeded upstairs. FitzGerald immediately attacked and wounded Swan who, according to most reports, retired, leaving the field to Ryan who, possessed of nothing but a sword-cane, grappled with FitzGerald and received fourteen severe wounds from a dagger, but managed to detain him until Sirr appeared and shot FitzGerald in the arm. Ryan was removed to a neighbour's house. He lingered ten days to write an account of the capture before dying of his wounds on 28 May. His funeral on 2 June in St Mary's church, Dublin, was attended by a large number of yeomanry. He left a wife and three young children who received a pension from the government of £200 a year.
His son, Daniel Frederick Ryan, became a barrister and assistant secretary in the excise office in London and enjoyed the patronage of Sir Robert Peel (qv). He guarded his father's memory jealously, holding to account all writers on the events of May 1798. Madden, while commending Ryan for bravery above that of the professional soldiers, wrote that ‘like Polonius he had the absurdity to thrust himself into a most dangerous position, and he suffered the sad consequences of his folly, in being taken for his betters’ (Madden, United Irishmen, ii, 433).