Ethel Carow Derby (née Roosevelt; August 13, 1891 – December 10, 1977) was the youngest daughter and fourth child of the President of the United States Theodore Roosevelt. Known as "The Queen" or "The First Lady of Oyster Bay" by its Long Island residents, Ethel was instrumental in preserving both the legacy of her father as well as the family home, "Sagamore Hill" for future generations, especially after the death of her mother, Edith, in 1948.