Harry Leith-Ross was born in Saint Pierre, Mauritius - an island in the South Indian Ocean - the son of banker Frederick William Arbuthnot Leith-Ross and Sina van Houten. His mother was the daughter of Dutch politician Samuel van Houten, and his younger brother was Scottish economist Sir Frederick Leith-Ross. Leith-Ross was educated in England and Scotland, and studied engineering at the University of Birmingham for a year. He emigrated to the United States at age 17 in 1903, and worked for his uncle's coal company. He subsequently took up advertising work in Denver, Colorado. He travelled to Paris in 1909, and studied art at the Académie Delécluse and the Académie Julian. He studied in New York City at the National Academy of Design School under Charles Yardley Turner, beginning in 1910. The Art Students League of New York operated a summer painting school in Woodstock, New York, which Leith-Ross first attended in 1913. His instructors included Birge Harrison and John F. Carlson. It was there that he met fellow student John Fulton Folinsbee, who would become his life-long friend. Folinsbee had contracted polio as a child, and was confined to a wheelchair. The two men shared a cabin, and Leith-Ross would carry Folinsbee around the countryside on his back. Each served as best man for the other's wedding. Folinsbee married in 1914, and he and his wife settled in New Hope, Pennsylvania in 1916, where Leith-Ross was a frequent houseguest. Both men painted en plein air, directly from nature. They were famous for spending afternoons sketching on the bridge at New Hope. Leith-Ross served as a second lieutenant in the United States Army during World War I. After the war, Leith-Ross taught at the University of Buffalo, and co-founded an art school in Rockport, Maine, where he taught during the summers. He met student Emily Slaymaker in Summer 1925, and they were married later that year. They lived in Woodstock, New York for a decade, then settled outside New Hope, Pennsylvania in 1935. They had one daughter, Elizabeth Leith-Ross Mow. He wrote a well-regarded book on landscape painting: Leith-Ross died in 1973 in Pineville, Pennsylvania.
Leith-Ross expressed his philosophy about painting in The Landscape Painter's Manual, Watson Guptill Publications. His works are in the permanent collections of the James A. Michener Art Museum, the Woodmere Art Museum, the Smithsonian American Art Museum, and many private collections. Leith-Ross's papers are at the University of Pennsylvania. The Michener Museum hosted a posthumous exhibition of his works, Poetry in Design: The Art of Harry Leith-Ross. Leith-Ross's Connecticut Valley in Fall was appraised on Antiques Roadshow in 2017.
