Hamilton, Malcolm (d. 1629), Church of Ireland archbishop of Cashel, was the son of Archibald Hamilton and either Maria Barkley of Ladeland or Anna Kennedy of Stamhasset Cassily. His father's provenance is uncertain; he may have been one of the Hamiltons of Raplock, Lanarkshire, Scotland. Malcolm Hamilton matriculated at St Andrews University in 1596 and graduated MA in 1600. Like many members of his extended family he settled in Ulster, becoming chancellor of Co. Down on 1 December 1612 and being denizated in 1616. In 1614 he purchased 100 acres at Deerynefogher in Magheraboy barony, Fermanagh, adding another 500 acres the next year. By 1619 he had built a castle there, at Monea; it is accounted among the finest of the plantation fortifications. He also had land interests in Down. In 1622 he became prebend of Devenish in Clogher.
On 23 May 1623 Hamilton was appointed archbishop of Cashel, being allowed to retain his previous benefices. He found his see's resources to be seriously depleted because of the alienations of his predecessor, Miler Magrath (qv). After drawing the king's attention to this in 1626 he was granted a number of clerical livings to supplement his income. He continued to take an interest in events in Fermanagh and was involved in government inquiries into the progress of the plantations. His appointment to the Irish privy council in July 1624 reflects his growing administrative commitments.
From the mid 1620s on he was one of the most prominent opponents of the crown's policy of de facto toleration of catholicism, being one of the twelve members of the Irish hierarchy signing a petition of condemnation in 1626. In April 1627 he preached at Christ Church against toleration, with James Ussher (qv), primate of Ireland. One year later he presented a petition from the Munster clergy to the king, to which he added his own composition, arguing that it was his duty to oppose heresy even in contravention of his king's wishes.
Hamilton died of fever 25 April 1629 in his house at Camus, near Cashel, and was buried in Cashel cathedral on 2 May. An inscription was erected in his memory there, but this was defaced during the reign of James II (qv).
He married first Mary, daughter of Robert Wilkin of Sackton Hall, with whom he had three sons; and secondly Jane Crawford, with whom he had three sons and four daughters. Neither marriage can be dated. Two of his sons, Hugh and Ludovic, fought with distinction in the Swedish army and were granted Swedish titles.