Winthrop Williams Aldrich GBE (November 2, 1885 – February 25, 1974) was an American banker and financier, scion of a prominent political family, and US Ambassador to the United Kingdom.
Aldrich was born in Rhode Island in 1885, the son of Nelson W. Aldrich. He attended Harvard University, receiving a bachelor's degree in 1907 and a J.D. degree in 1910.
During the First World War Aldrich had built, at his own expense, the patrol boat USS Herreshoff No. 309 which was leased by Aldrich to the U.S. Navy and patrolled the waters off of Rhode Island from 15 November 1917 to 31 December 1918 when it was returned to Aldrich.
Aldrich had been commissioned a lieutenant (junior grade) in the Naval Reserve and was called to active duty on April 8, 1917 and was assigned to the Naval Training Station in Newport, Rhode Island. He transferred to the USS Niagara (SP-136) in September and was assigned as the ship's navigator. He was reassigned to the USS New Orleans (CL-22) in June 1918 and served on convoy duty. He was promoted to lieutenant on June 1 of the same year and, after the armistice, was released from active duty in December.