George Dudley Seymour (October 6, 1859 - June 21, 1945) was an American historian, patent attorney, genealogist and city planner. He was born and raised in Bristol, Connecticut and practiced patent law in New Haven, Connecticut. Seymour was a law graduate of Columbian College in Washington, D.C. [now George Washington University], and received an honorary Master of Arts degree from Yale University in 1913. He was a member of the Acorn Club, to which he was elected in 1920, and a member of the Walpole Society, to which he was elected in 1918. Seymour was a former vice president of the American Federation of Arts and a trustee of the Wadsworth Atheneum. He was a close friend of William Howard Taft and a cousin of Yale President Charles Seymour.
Seymour extensively researched the life of the patriot Nathan Hale. He led the campaign for the statue of Hale on the Old Campus at Yale, and convinced the federal government to print a Nathan Hale postage stamp in 1925. In 1914, Seymour purchased the Nathan Hale Homestead in Coventry, Connecticut, which he restored and gifted to the Antiquarian & Landmarks Society.
The George Dudley Seymour Papers, Seymour's collection of correspondence, writings, photographs, research files, and printed material, are housed within the Manuscripts and Archives in Sterling Memorial Library at Yale.
George Dudley Seymour State Park in Middlesex County, Connecticut is named after him.