Francis Seymour-Conway, 1st Marquess of Hertford (5 July 1718 – 14 June 1794) of Ragley Hall, Arrow, in Warwickshire, was a British courtier and politician who, briefly, was Viceroy of Ireland where he had substantial estates.

He appointed David Hume as his Secretary, who wrote of him, "I do not believe there is in the World a man of more probity & Humanity, endowd with a very good Understanding, and adornd with very elegant Manners & Behaviour".

The Speaker of the Irish House of Commons, John Ponsonby, was satisfied that "the public as well as private character of Lord Hertford, together with the great property which he has in Ireland" were "the best securities which we can have for his good behaviour.

But with his eldest son, Francis, Viscount Beauchamp, as his chief secretary, Hertford was in Ireland for just one parliamentary session (October 1765–June 1766).

[7] In 1782, when she was only fifty-six, his wife died after having nursed their grandson at Forde's Farm, Thames Ditton, where she caught a violent cold.

He enjoyed this elevation for almost a year until his death at the age of seventy-six, on 14 June 1794, at the house of his daughter, the Countess of Lincoln.

Her grandfather was Henry FitzRoy, 1st Duke of Grafton (1663–1690), an illegitimate son of King Charles II.

By his wife he had thirteen children: He is not known to have suffered himself from any mental abnormality, but a noted strain of eccentricity, even madness, appeared among his descendants: the debauched behaviour of his grandson, the 3rd Marquess, and the suicide of another grandson, Viscount Castlereagh, were both attributed to a strain of madness supposed to be hereditary in the Seymour Conway family.