James Roosevelt "Tadd" Roosevelt, Jr., (1879–1958) was a member of the Roosevelt family and the Astor family. He was the son of James Roosevelt "Rosey" Roosevelt (son of James Roosevelt and Rebecca Howland) of the Roosevelts and Helen Schermerhorn Astor (daughter of William Backhouse Astor, Jr. and Caroline Webster Schermerhorn) of the Astors. Tadd was also the nephew of President Franklin Delano Roosevelt and John Jacob Astor IV. Tadd's sister was Helen Rebecca Roosevelt Robinson
As children, Franklin never really cared much for Tadd, who pulled their cousin Alice Roosevelt's hair. However, Franklin and Helen were friendly, and at times they did play with Tadd. Franklin and Tadd also played "Little Princess in the Tower" for a tableau after dinner.
Both Franklin and Tadd attended Groton School and Harvard University at the same time. However, Tadd quit Harvard amid scandal. He eventually moved to New York City, where he married Sadie Messinger, a Hungarian-born prostitute, with whom he stayed until her death forty years later.
Considered a black sheep of the Roosevelt clan, Rosey disowned Tadd, and all relations with the Roosevelt family were ended. He never touched his inheritance from his mother's family, the Astors, bequeathing his estate to the Salvation Army upon his death in 1958.