Guido Norman Lieber (May 21, 1837, Columbia, South Carolina – April 25, 1923[1]) was a United States Army lawyer and jurist.

He graduated from the University of South Carolina in 1856, and at Harvard Law School in 1859, and in that year was admitted to the bar of New York.

At the beginning of the Civil War he became 1st lieutenant in the 11th infantry, U.S. Army, and was appointed regimental adjutant, and served during the peninsular campaign under George B. McClellan, being brevetted captain for gallantry at the Battle of Gaines' Mill on June 27, 1862.

In 1862 he was appointed major and judge advocate, and he served in this capacity in the Department of the Gulf, being present in the Teche and Red River campaigns.

05226) of the Military Order of the Loyal Legion of the United States, the first post-Civil War veterans' organization, founded by and for men who had served as commissioned officers in the armed forces of the Union.