Hall Hartson was an Irish poet and playwright who produced only a few works, one of which was the tragedy The Countess of Salisbury (1767), adapted from Thomas Leland’s novel Longsword (1762).

In his Observations on Man, his Frame, his Duty, and his Expectations (1749), physician David Hartley expounded a physiological theory of "vibrations" to explain his conviction that the moral sense was not inborn, but rather a consequence of the association of ideas. Particularly after his work was popularized by Joseph Priestley in his abridgment Hartley's Theory of the Human Mind on the Principle of the Association of Ideas (1775), Hartley's ideas exerted broad influence on literature, philosophy, medicine, psychology, and issues such as education and reform.

Prominent English actor and Royalist soldier during the English Civil War, most likely the son of William Hart, nephew of William Shakespeare. Hart was known for his natural air of dignity which resulted in his frequently playing royal roles.

Political philosopher James Harrington authored The Common-wealth of Oceana (1656), in which he promotes his ideas on the ideal design of a republic.

Also Harpocrates; the Greek version of one aspect of the Egyptian god Horus, who represented in this form the rising sun.

Ancient writer whose work is known through later quotations rather than through surviving texts.

See Oxford, Robert Harley, Earl of, 1661-1724.

A late fourteenth and early fifteenth-century soldier turned historian, author of The Chronicle of John Hardyng, printed in London by Grafton in 1543 and recently suggested as a source for Sir Thomas Malory's Morte Darthur.

The 1st Earl Harcourt, known as the Viscount Harcourt between 1727 and 1749, Simon Harcourt was a British general and diplomat who served as the Lord Lieutenant of Ireland from 1772 to 1776.

The 2nd Earl Harcourt, styled Viscount Nuneham until inheriting the title of Earl Harcourt in 1777, George Harcourt was an English politician and patron of the arts.