Penn, of Laleham in Middlesex, was the second son of Richard Penn, Sr. and the grandson of William Penn, the founder of Pennsylvania. He was educated at Eton College and St John's College, Cambridge before joining the Inner Temple. In 1763 he and his brother John visited Pennsylvania, of which his family were still sole proprietors. He was qualified as a councilor on 12 January 1764. During 1768 he was elected as a member of the American Philosophical Society. In 1771 he returned to Pennsylvania and was appointed lieutenant governor. He soon became acting governor when his brother returned to England to attend to the colony's legal interests. He proved popular with the provincials, taking much care over their commercial interests, but less so with his uncle, the proprietor. After two years he was supplanted by the re-appointment of his brother as governor. . Penn's city house later served as the presidential mansion of George Washington and John Adams, 1790–1800. On 21 May 1772, at Christ Church, Philadelphia, he married Mary "Polly" Masters, daughter of the late William Masters of Philadelphia. The bride's mother gave them a splendid city house as a wedding present. Penn entertained members of the Continental Congress at his Philadelphia city house, a Virginia delegate, Colonel George Washington, being among his guests. Richard Penn was elected a trustee of the College and Academy of Philadelphia in 1772, serving as president of the board in 1773 and 1774. With the coming of the Revolution, he retired and returned to England in the summer of 1775, when the Continental Congress entrusted him with the Olive Branch Petition to the King. George III refused to accept the petition, but Penn gave evidence to the House of Lords on the colonies' attitudes toward independence. After the conclusion of the American Revolution, he was allowed compensation by the US government for the loss of his proprietary rights in Pennsylvania, and visited Philadelphia again in 1808. James Boswell records that in 1789 the influential Earl of Lonsdale urged the government to appoint Penn as Britain's first Ambassador to the United States, although nothing came of the idea. Penn entered Parliament in 1784 as member for Appleby, elected on the Lonsdale interest, and subsequently also represented two other Lonsdale-dominated boroughs, Haslemere and Lancaster. He was a reliable supporter of Pitt's government, but rarely if ever spoke in the House of Commons. He resigned his seat in 1791, but returned to Parliament at the next general election, in 1796. Richard and Mary Penn had two sons, William Penn and Richard Penn, FRS, and two daughters, Hannah, who died without issue and Mary who married Samuel Paynter. He died at Richmond-on-Thames in 1811.
