George Grenville, Earl Temple's nephew, was extremely wealthy when he inherited Stowe, thanks to his marriage to Irish heiress Mary Nugent.

While his brother and his cousin, William Pitt the Younger, became Prime Minister, George Grenville did not reach the top of the political tree. In fact, the eventual loss of office and subsequent drop in income for all three Grenville brothers left expansion plans for Stowe seriously underfunded.

Of his changes, the biggest were to the grand approaches, realigning the main drive at an angle to the house. He also planted the Oxford Avenue, added two columns near the Corinthian Arch and built the barracks and the two Buckingham Lodges.

With money relatively short, he repaired rather than revamped the garden, reusing an old chimneypiece for the Seasons Fountain, redecorating the Queen's Temple in 1790 and enclosing the Cobham Monument in another twenty eight acres of garden. He also completed his uncle's clearance of unwanted buildings and had the Menagerie built for his wife, who in turn founded a school at the back of the Orangery.

It became a venue for family fun as much as grand gestures to exalted guests, with informal balls and parties, skating and rowing on the lakes, and lunches that were opened to locals. Important figures, however, continued to enjoy Stowe, the most famous of whom were the exiled Louis XVIII of France and seven relatives in 1808, leading to the re-naming of the Keeper's Lodge as the Bourbon Tower. The future George IV and William IV stayed at Stowe in 1805.