Sir Philip Francis GCB (22 October 1740 – 23 December 1818) was an Irish-born British politician and pamphleteer, thought to be the author of the Letters of Junius, and the chief antagonist of Warren Hastings.

Born in Dublin, he was the only son of Dr Philip Francis (c. 1708–1773), a man of some literary celebrity in his time, known by his translations of Horace, Aeschines and Demosthenes.

He received the rudiments of an excellent education at a free school in Dublin, and afterwards spent a year or two (1751–1752) under his father's roof at Skeyton Rectory, Norfolk, and elsewhere, and for a short time he had Edward Gibbon as a fellow-pupil.

In 1756, immediately on his leaving school, he was appointed to a junior clerkship in the secretary of state's office by Henry Fox (afterwards Lord Holland), with whose family Dr Francis was at that time on intimate terms; and this post he retained under the succeeding administration.

In January 1769 Philip Francis returned to London from a 'riotous fortnight' in Bath where he lived as a 'raike';[1] later that year he became one of the original shareholders in the project to build a new Assembly Rooms in the city.

It was natural that Francis, who from a very early age had been in the habit of writing occasionally to the newspapers, should be eager to take an active part in the discussion, though his position as a government official made it necessary that his intervention should be carefully disguised.

Comparing stylistic patterns from the letters with attributed writings of the period allowed a reasonable statistical conclusion to be drawn that Francis was by far the most likely author.

These three, actuated probably by petty personal motives, combined to form a majority of the council in harassing opposition to the governor-general's policy; and they even accused him of corruption, mainly on the evidence of Nuncomar.

Although excluded by a majority of the House of Commons from the list of the managers of that impeachment, Francis was nonetheless its most energetic promoter, supplying his friends Edmund Burke and Richard Sheridan with all the materials for their eloquent orations and burning invectives.

In 1793 he supported Earl Grey's motion for a return to the old constitutional system of representation, and so earned the title to be regarded as one of the earliest promoters of the cause of parliamentary reform; and he was one of the founders of the Society of the Friends of the People.

His disappointment was great when the governor-generalship was, owing to party exigencies, conferred on Sir Gilbert Elliot (Lord Minto); he declined, it is said, soon afterwards the government of the Cape, but accepted a KB.