Archibald Kennedy IV, Earl of Cassillis (4 June 1794 â 12 August 1832), styled Lord Kennedy until 1831, was a Scottish aristocrat and Member of Parliament. He was the eldest son and heir of Archibald Kennedy, 1st Marquess of Ailsa but died before his father.
Archibald was the eldest son of Archibald Kennedy, 1st Marquess of Ailsa and the former Margaret Erskine. Among his younger siblings were Lady Anne Kennedy (wife of Sir David Baird, 2nd Baronet), Lady Margaret Radclyffe Livingstone Eyre, John Kennedy-Erskine (who married Lady Augusta FitzClarence, an illegitimate daughter of King William IV), and Lady Alicia Jane Kennedy (wife of Jonathan Peel, Secretary of State for War).
His father was the eldest son of Archibald Kennedy, 11th Earl of Cassillis, by Anne Watts (a daughter of John Watts and descendant of the Schuyler family, the Van Cortlandt family, and the Delancey family of British North America).
He studied at the University of Saint Andrews under the tutorage of James Ferrie, Professor of Civil History.
As the eldest son of his father, he became known by the courtesy title Lord Kennedy until 10 September 1831, when his father was elevated to the marquessate of Ailsa. From that point he was known as the Earl of Cassillis until his death (never succeeding to the marquessate).
Lord Cassillis served as a Member of Parliament for Evesham from 1830 to 1831.
On 1 May 1814, Kennedy married Eleanor Allardyce, daughter and heiress of Alexander Allardyce of Dunnottar, Kincardine. Together, they had three daughters and nine sons, including:
Lord Cassillis died on 12 August 1832, before he could succeed to the marquisate. His eldest son, Archibald, succeeded his grandfather as the 2nd Marquess of Ailsa on 8 September 1846. His widow died three months later.