Lloyd Llewellyn Black (March 15, 1889 – August 23, 1950) was a United States federal judge.
Born in Leavenworth, Kansas, Black received an A.B. from the University of Washington in 1910 and an LL.B. from the University of Washington School of Law in 1912. He was in private practice in Everett, Washington for various periods between 1913 and 1932. He was a special counsel to the City of Everett in 1916 and from 1920 to 1922, and a prosecuting attorney of Snohomish County, Washington from 1917 to 1919. He served in the United States Army towards the end of World War I, in 1918, and was later an attorney in the U.S. Army at the Port of Everett from 1923 to 1936. Black was a judge on the Superior Court, Snohomish and Island Counties, Washington from 1936 to 1939.
On August 2, 1939, Black was nominated by President Franklin D. Roosevelt to a new seat on the United States District Court for the Western District of Washington created by 52 Stat. 584. He was confirmed by the United States Senate on August 4, 1939, and received his commission on August 11, 1939. On January 20, 1940, Black was reassigned by operation of law to also sit on the United States District Court for the Eastern District of Washington. Black served in both districts until his death, in 1950.