William Worthington Russell Jr. (December 3, 1858 – March 11, 1944) was an American diplomat who served under five presidents.

He also served as senior watch officer of the Brazilian cruiser America, which was delivered at the time of the Melo revolution in 1893.

He presented his credentials on December 9, 1904, and served until he left his post on May 24, 1905,[8] when "he was summoned to Washington as a witness in the investigation of the charges preferred by Herbert W. Bowen, Minister to Venezuela, against Assistant Secretary of State Loomis.

Envoy Extraordinary and Minister Plenipotentiary to Venezuela and he was commissioned during a recess of the U.S. Senate.

[8] On June 24, 1910, he was appointed by President William Howard Taft as the Minister Resident/Consul General to the Dominican Republic and presented his credentials on November 3, 1910.

On September 5, 1911, he was promoted to Envoy Extraordinary and Plenipotentiary to the Dominican Republic and presented his credentials the same day.

He was commissioned during a recess of the Senate and presented his credentials on October 7, 1915, before being recommissioned on December 17, 1915, after confirmation.

[8] On September 28, 1925, he received his final diplomatic appointment from President Calvin Coolidge as U.S.