Brodrick, Sir St John (1627–1711), soldier and politician, was born 3 December 1627, fourth son of Sir Thomas Brodrick of Wandsworth, Surrey, England, lieutenant-governor of the Tower of London, and his wife Katharine Nicholas, of Manningford Bruce, Wiltshire. The family had prior connections with Ireland. Two ancestors, Capt. Thomas Brodrick (d. 6 May 1547) and Edward Brodrick (d. c.1585), died there, while another, John Brodrick, sold inherited lands in Ireland in the reign of Henry VIII.
Brodrick himself came to Ireland in 1641 as a captain of foot, serving in Munster; in 1649 he commanded a company in the regiment of Sir Percy Smyth. He defected to parliament with the Cork garrison in October alongside Richard Townsend (qv), and signed the 1649 remonstrance of the Munster army repudiating the treaty between Murrough O'Brien (qv), earl of Inchiquin, and the confederates. After service in Scotland, Brodrick returned to Ireland after the battle of Worcester in 1651. After the disbandment of his troop (1654) he settled in Kerricurrihy, Co. Cork. In April 1654 he petitioned for c.1,000 acres in Barrymore. While initially refused, the request was largely met, and in 1657 he was granted forfeited lands in Kilbroney. A comrade of Roger Boyle (qv), Lord Broghill and later earl of Orrery, Brodrick was his sometime provost-marshal, and they were close neighbours, as Brodrick had lands in Barrymore.
Brodrick was elected to the 1660 Dublin convention for Clonakilty. In February 1661 he commanded a troop of horse, being granted command of a company previously earmarked for disbandment. He was knighted on 20 March 1661. In April 1661 Orrery requested a pardon for him, and on 30 July this was granted for all activities prior to 29 December 1660. Distrusted by the viceroy James Butler (qv), duke of Ormond, Brodrick survived, aided by the undoubted royalism of his elder brother Alan (qv), surveyor general of Ireland. Returned as MP for Kinsale in May 1661, in October 1661 he was appointed provost-marshal of Munster. In July 1662 he was commissioned to command a company of foot, and was one of a number of Munster officers to sign a loyal declaration to Ormond; in 1662 he also became high sheriff of Cork. Under the terms of the act of settlement, Brodrick continued to amass property in Cork, in Ballyclough, Ballygriggan, and Templeroan, and in 1666 he successfully obtained lands at the expense of Edward Synge (qv), bishop of Cork, Cloyne, and Ross. During the 1660s he built, and resided at, a manor house at Ballynannan. Following a petition, in May 1668 his lands were converted into the corporation and borough of Middleton, a move prompted in part by rivalry with Inchiquin. In 1669 he became deputy governor of Co. Cork, and in April 1670 Middleton was granted manorial status, with manorial rights granted in June. He came to reside there and built up the town, which became the basis of a powerful family interest in the county. He retained his commands throughout the period, leaving the army c.1679, though in the 1670s he resided for a period at Wandsworth. Throughout the restoration Brodrick remained close to Orrery, being closely involved in both the running of his property and in the construction of his residence at Charleville; while in London he oversaw Orrery's Somerset estate. After Orrery's death (1680) he remained a close ally of the Boyles. His assistance to them was seen as a given, though profit was occasionally suggested as a motive. However, in August 1683 Brodrick fended off encroachments on Boyle lands, though in July 1688 he was accused of treating their tenants harshly.
The family took refuge in England during the Glorious Revolution, and Brodrick was attainted by the Jacobite parliament of 1689. Later in the year he was chosen, along with his son Alan (qv), to represent Munster in proposing the settlement of Ireland to William of Orange (qv). In 1690 a petition was apparently gathered beseeching Brodrick, given his military experience, to raise a regiment in defence of Munster protestants during the Williamite war, being ‘one who has at all times since been a zealous assertor (to his own great hazard) of the protestant interest’ (Sir St John Brodrick's vindication, 5). He offered to raise one from Munster refugees in London in the latter half of 1690, though he was accused of surreptitiously doing so anyway, allegedly maintaining a private force for five months by defrauding relief funds, in order to profit from further confiscations; the allegations prompted a furious rebuttal. In 1692–3 he was MP for Co. Cork, serving on two committees and favouring the commons' claim to the ‘sole right’ of initiating the heads of money bills; he was elected again to the 1695–9 parliament and appointed to seventy-six committees, though his age qualified him for exemption. In 1699 he was deputy governor of Cork city and county. Brodrick died in January 1711, and was buried in Wandsworth.
He married (1653) Alice Clayton (d. 1696), daughter of Laurence Clayton of Mallow, Co. Cork, clerk of the Munster council; they had six sons and a daughter. Of his sons, four sat in parliament: Thomas (qv), St John, William, and Alan, a leading advocate of the ‘sole right’ who later became lord chancellor, and was created 1st Viscount Midleton. The youngest son, Laurence, was chaplain of the English house of commons in 1708.