Isaac Newton Phelps Stokes (1867–1944) was an American architect, who was the eldest son of Helen Louise (Phelps) and Anson Phelps Stokes. His early architectural career was in partnership with John Mead Howells. Stokes was a pioneer in social housing who co-authored the 1901 New York tenement house law. For twenty years he worked on the The Iconography of Manhattan Island, a six volume compilation that became one of the most important research resources about the early development of the city. His designs included St. Paul's Chapel at Columbia University and several urban housing projects in New York City. He was also a member of the New York Municipal Arts Commission for twenty-eight years and president for nine of these.
He was educated at St. Paul's School, Concord, and Berkeley School in New York City before graduating from Harvard in 1891. He later took post graduate courses at Columbia University and then Italy before studying for three years at the Ecole des Beaux-Arts in Paris. He married Edith Minturn — daughter of Sarah Susannah Shaw and Robert Bowne Minturn, Jr. — in 1895 at La Malbaie, Quebec, Canada. They lived in Paris whilst Stokes continued his studies. A friend sponsored their famous portrait in oil, by John Singer Sargent, as a wedding gift. Edith also served as the artist's model for a well-known sculpture, Statue of the Republic by Daniel Chester French, and a portrait by Cecilia Beaux. She was President of the New York Kindergarten Association. She was the aunt of Edie Sedgewick, who was named after her.