Theodore Roosevelt Sr. was an American businessman and philanthropist from the Roosevelt family. Roosevelt was also the father of President Theodore Roosevelt and the paternal grandfather of First Lady Eleanor Roosevelt. He served as a member of the plate-glass importing business Roosevelt & Son.

The Roosevelt family is an American political family from New York whose members have included two United States presidents, a First Lady, and various merchants, bankers, politicians, inventors, clergymen, artists, and socialites. The progeny of a mid-17th century Dutch immigrant to New Amsterdam, many members of the family became nationally prominent in New York State and City politics and business and intermarried with prominent colonial families. Two distantly related branches of the family from Oyster Bay and Hyde Park, New York, rose to global political prominence with the presidencies of Theodore Roosevelt (1901–1909) and his fifth cousin Franklin D. Roosevelt (1933–1945), whose wife, First Lady Eleanor Roosevelt, was Theodore's niece. The Roosevelt family is one of four families to have produced two presidents of the United States by the same surname; the others were the Adams, Bush, and Harrison families.