Warren Delano Robbins was born on September 3, 1885, in Brooklyn, New York and named after his maternal grandfather, Warren Delano Jr.  He was the son of Katherine Robbins Delano (1860–1953) and Charles Albert Robbins (1854–1889).
From his parents marriage, he had one sibling, sister Muriel Delano Robbins (wife of Cyril Edgar Martineau of London).
After his father's death in 1889, his mother remarried to Hiram Price Collier, a Unitarian minister,  and they lived in a mansion in Tuxedo Park, New York.
From his mother's second marriage, he was the older half-brother of Sara Roosevelt Collier (wife of Englishman Charles Fellowes-Gordon) and Katharine Price Collier, a Republican U.S. Representative who in 1917 married George St. George, third son of the second Sir Richard St George, 2nd Baronet.

His paternal grandfather was Daniel Robbins, one of the founders of McKesson, Robbins & Co.  His maternal grandfather was a wealthy and prominent merchant who lived in China during the 1830s and he was a direct descendant of Philip Delano, a Pilgrim who arrived in Plymouth, Massachusetts in 1621.
Among his large extended family was aunt Deborah Perry Delano (wife of William Howell Forbes) uncle Warren Delano IV, aunt Sara Ann Delano (wife of James Roosevelt I), and uncle Frederic Adrian Delano.

After attending the Groton School, which was run by Rev. Endicott Peabody in Groton, Massachusetts (where his cousin Franklin, who was three and a half years older than him, also attended), he graduated from Harvard University in 1908.
Warren Delano Robbins was born on September 3, 1885, in Brooklyn, New York and named after his maternal grandfather, Warren Delano Jr.  He was the son of Katherine Robbins Delano (1860–1953) and Charles Albert Robbins (1854–1889). From his parents marriage, he had one sibling, sister Muriel Delano Robbins (wife of Cyril Edgar Martineau of London). After his father's death in 1889, his mother remarried to Hiram Price Collier, a Unitarian minister,  and they lived in a mansion in Tuxedo Park, New York. From his mother's second marriage, he was the older half-brother of Sara Roosevelt Collier (wife of Englishman Charles Fellowes-Gordon) and Katharine Price Collier, a Republican U.S. Representative who in 1917 married George St. George, third son of the second Sir Richard St George, 2nd Baronet.
His paternal grandfather was Daniel Robbins, one of the founders of McKesson, Robbins & Co.  His maternal grandfather was a wealthy and prominent merchant who lived in China during the 1830s and he was a direct descendant of Philip Delano, a Pilgrim who arrived in Plymouth, Massachusetts in 1621. Among his large extended family was aunt Deborah Perry Delano (wife of William Howell Forbes) uncle Warren Delano IV, aunt Sara Ann Delano (wife of James Roosevelt I), and uncle Frederic Adrian Delano.
After attending the Groton School, which was run by Rev. Endicott Peabody in Groton, Massachusetts (where his cousin Franklin, who was three and a half years older than him, also attended), he graduated from Harvard University in 1908.
Warren Delano Robbins