Winslow Warren was an American attorney who served as Collector of Customs for the Port of Boston during the second administration of Grover Cleveland.
Warren was born on March 20, 1838 in Plymouth, Massachusetts to Dr. Winslow Warren and Margaret Bartlett Warren. His great-grandparents were James and Mercy Otis Warren.
Warren attended public schools in Plymouth. He then graduated from Harvard College in 1858 and Harvard Law School in 1860. He completed his legal training in the office of his uncle, Sidney Barnett, and was admitted to the Massachusetts bar in March 1861.
On January 3, 1867, Warren married Mary Lincoln Tinkham of Boston. The couple took up residence in Dedham, Massachusetts.
Warren was a director of the Columbian National Life Insurance Company and for many years served as legal counsel for the Boston and Providence Railroad. From 1899 to 1911, Warren was an overseer of Harvard University.
Warren served as president general of the Massachusetts Society of the Cincinnati and was the vice president of the Society's national organization. He was also president of the University Club, the Unitarian Club of Boston, and the Massachusetts Reform League and the vice president of the Massachusetts Historical Society.
Warren also served a president of the L'Enfant Memorial Association, which sought to arouse interest in the erection of a monument to Pierre Charles L'Enfant on the National Mall and vice president of the Bunker Hill Monument Association.
Warren was a life-long member of the Democratic Party was a prominent figure in public affairs in Dedham, Massachusetts. He served as president of the Dedham Water Company. In 1908, Warren broke with the Democratic Party and supported Republican William Howard Taft over William Jennings Bryan.