Frederick Lincoln Siddons (November 21, 1864 – June 19, 1931) was an Associate Justice of the Supreme Court of the District of Columbia.

Born on November 21, 1864, in London, England, Siddons received a Bachelor of Laws in 1887 and a Master of Laws in 1888, both from Columbian University School of Law (now George Washington University Law School). He was employed with the United States Department of the Treasury starting in 1888. He entered private practice in Washington, D.C. starting in 1890. He was a Professor of Law at National University School of Law (now George Washington University Law School) from 1898. He was a member of the Commission on Uniform State Laws for the District of Columbia.^[1]

Siddons was a United States Commissioner for the Supreme Court of the District of Columbia from 1913 to 1915.^[1]

Siddons was nominated by President Woodrow Wilson on December 9, 1914, to an Associate Justice seat on the Supreme Court of the District of Columbia (now the United States District Court for the District of Columbia) vacated by Associate Justice Daniel Thew Wright. He was confirmed by the United States Senate on January 15, 1915, and received his commission the same day. His service terminated on June 19, 1931, due to his death in Washington, D.C.^[1]