Jefferson Borden Harriman (September 20, 1864 – December 2, 1914) was a New York financier and member of the Gilded Age's “hunting set.” He was best known as the supportive husband of Florence Jaffray Harriman, a socialite who became a progressive social activist and (after his death) a United States Ambassador to Norway during the administration of President Franklin D. Roosevelt. He was a cousin of railroad tycoon Edward Harriman, who was the father of statesman and diplomat W. Averell Harriman. A lingering gastrointestinal problem led to his early retirement and death.