Campbell, Lord Frederick (1729–1816), politician, chief secretary, was born 20 June 1729, third son among four sons and three daughters of John, 4th duke of Argyll, and his wife Mary, daughter of John, 2nd Lord Belleden. Educated at Westminster (1743–6) and Christ Church, Oxford (1747–51), he was called to the bar in 1754. Much of his early success was due to the patronage of his cousin Lord Bute. Elected MP for the Glasgow burghs (1761–80) and for Argyllshire (1780–99), he consistently supported the government. He also sat (1767) in the Irish house of commons for Thomastown, Co. Kilkenny, before being elected for St Canice, Kilkenny (1768–76). He was a poor parliamentarian, rarely contributing to debates, especially after 1772. In 1765 he became lord keeper of the Scottish privy seal, holding the position for a few months before being succeeded by Lord Breadalbane. He was appointed to the privy council on 29 May 1765.
His main contribution to Irish affairs came with his appointment (1767) as chief secretary to Lord Townshend (qv). It was a position he neither sought nor wanted, and accepted only when he had failed to obtain the office of vice-admiral of Scotland. Installed in what he called ‘this troublesome office’ of chief secretary, he acted as a liaison between the government in London and Townshend, who (unlike previous viceroys) chose to reside in Dublin. However, he served for only a short time, and when offered the prestigious position of lord clerk register for Scotland in 1768 he resigned as chief secretary and was replaced by George Macartney (qv) on 1 January 1769, bringing his term of office to an unsatisfactory end. In 1777 he was confirmed as lord clerk register for life. Thereafter he enjoyed his self-confessed ‘idleness’, although he accepted a number of positions in the 1780s. He became vice-treasurer for Ireland (1787–93) and in 1790 became a member of the board of control for India.
He married (28 March 1769) Mary, youngest daughter of Amos Meredith of Henbury, Cheshire, and widow of Laurence, 4th Earl Ferrers. She died tragically, burnt to death (1807) in his house at Comb Bank, Kent. He died 8 June 1816 in Queen St., Mayfair, London, and was buried in the family vaults at Sandridge, Kent. He had no legitimate issue.