Elliott Bulloch Roosevelt was the third of the four children of Theodore Roosevelt Sr. (1831–1878) and Martha Stewart “Mittie” Bulloch (1835–1884). In addition to elder brother Theodore Jr., he had a younger sister named Corinne (1861–1933) and an elder sister named Anna (1855–1931), who was known as “Bamie”. Mittie’s brothers Irvine (1842–1898) and James (1823–1901) were Civil War Confederate veterans who accompanied Elliott when he left Europe in 1892 to admit himself into an asylum in Virginia. Elliott Bulloch Roosevelt had a competitive relationship with his older brother. As an Oyster Bay Roosevelt, and through his ancestor Cornelius Van Schaack, Jr., Elliott was a descendant of the Schuyler family.  At a young age, Elliott was academically more successful than Theodore; however, he was eventually surpassed by his older brother. This competition would continue into the next generation with their own daughters. Elliott enrolled at St Paul’s School in Concord, New Hampshire in September 1875. He performed well academically though had to soon withdraw and return home after unexpectedly falling ill. Elliott maintained a charming and winsome personality all his life, which masked a growing drinking problem that started at a young age. Elliott was Theodore’s best man on October 27, 1880, on Theodore’s first marriage to Alice Hathaway Lee. In 1883, Elliott married Anna Rebecca Hall (1863—1892), the eldest daughter of Valentine Gill Hall, Jr. and Mary Livingston Ludlow, on December 1, 1883, in Calvary Church in Gramercy Park, New York City.

Due to his drinking problem, Elliott Bulloch Roosevelt was exiled to Abingdon, Virginia, where he would constantly write letters, mostly to Eleanor. Eleanor later recalled that on his many horseback riding expeditions with the young children in Virginia, he became attached to “one girl in particular of whom I was jealous.” On occasion, he would, to the jubilation of Eleanor, return home for a few days. Theodore Roosevelt became the conservator for his spendthrift brother. At the age of 34, Elliott attempted suicide by jumping out a window; he survived the initial fall, but suffered a seizure and died a few days later. At the time of his death, his alcoholism had escalated such that he was consuming numerous bottles of Champagne and brandy each day.