Andrew Christian Tychsen[1] (June 27, 1893 – July 3, 1986) was a United States Army brigadier general.

[2] During World War I, Tychsen enlisted as a private in the Minnesota National Guard in April 1914 and was assigned to Company A of the 1st Infantry.

He rose to the rank of first sergeant and was posted to the First Reserve Officers Training Camp at Fort Snelling on March 25, 1917.

On August 1, 1935, Tychsen was promoted to the rank of major and was detached to the Command and General Staff School at Fort Leavenworth, Kansas.

During the Korean War, Tychsen was served as Chief of Staff of the IX Corps, under command of Major General Willard G. Wyman.