Hill House International Junior School, known simply as Hill House, is an independent preparatory day school primarily in the Knightsbridge district of London (with a boarding house in Glion, Canton Vaud, Switzerland). It was founded in September 1949 by athlete and Liberal Party politician Lt-Col Stuart Townend along with his wife, Beatrice. Initially only in Switzerland, the school soon established branches in South West London. It is the largest preparatory school in London and was originally an all-boys school, turning fully coeducational in 1981. The school educates children belonging to over 60 nationalities, and most pupils are bi- or trilingual.
In 2025, Hill House was ranked by Spear's to be amongst the “100 leading private schools in the world” alongside other British prep schools including the Dragon School and Westminster Under School and senior schools including Eton College, Wellington College, and Wycombe Abbey. Besides notable alumni in politics and the arts, Hill House is famous for its distinct and eccentric uniform, designed by Beatrice Townend to be all-purpose and from the belief that “Grey school uniforms make for grey minds.” The uniform includes thick golden cable-knit jumpers, burgundy-coloured corduroy knickerbockers, cravats in the school colours, and backpacks in British racing green.