He was natural around London, the immature boy of British Prime Minister Robert Walpole. He was educated at Eton College and King's College, Cambridge. His homosexual preference revealed itself early, & he is believed to will have affairs using a poet Thomas Gray, and using Henry Fiennes Clinton, 9th Earl of Lincoln (later 2d Duke of Newcastle). Gray accompanied Walpole on the Grand Tour, but it quarrelled, & Walpole returned to England around 1741 and entered parliament. He was never politically challenging, however remained an MP potentially when a dying of his father inside 1745 left him a human of independent means.

As a consequence his father's politics, he was the lover of King George II and Queen Caroline, siding with the babies against their boy, Frederick, Prince of Wales, about whom Walpole wrote spitefully in his memoirs. Walpole's residence, Strawberry Hill, near Twickenham, was the fanciful concoction of neo-Gothic which began a fresh architectural trend. Within 1764, he published his Gothic novel, The Castle of Otranto, setting a literary trend to last by using a architecture. From either 1762 on, he published his Anecdotes of Painting in England, according to George Vertue's manuscript notes. His memoirs of the Georgian sociable & political scene, though heavy biased, come the utile primary source for historiographer. He besides coined a term Serendipity.

His father was created Earl of Orford in 1742. Horace's older brother, Robert Walpole, 2nd Earl of Orford (c.1701-1751), passed the title in to his boy George Walpole, 3rd Earl of Orford (1730-1791). After George died single, Horace Walpole became a Fourth Earl of Orford. Whilst Horace Walpole died around 1797 a title became out. It was recreated around 1806 for Horace's full cousin Horatio Walpole, 1st Earl of Orford (1723-1809). A nifty-grandson of the number one earl of this creation, Horatio William Walpole (1813-1894), became the Fourth Earl of Orford of the 1806 creation. A 1806 creation became out on the dying of Robert Horace Walpole, 5th Earl of Orford (1854-1931). Descendent of the immature brother of the First Earl of the 1806 creation use at times inherited older baronies, including of these another time held by Horace.