Leopold von Gilsa (died March 1, 1870) was a career soldier who served as an officer in the armies of Prussia and later the United States.

He is best known for his role in the misfortunes of the XI Corps in the Army of the Potomac during the American Civil War, particularly at the battles of Chancellorsville and Gettysburg, where many of his men were unjustly accused of cowardice.

He moved to the United States and settled in New York City, where he taught and played the piano and sang in the music halls along the Bowery.

[4] Minus its leader, von Gilsa's regiment served in the brigade of Julius Stahel under Maj. Gen. Franz Sigel in the Second Battle of Bull Run.

When Sigel's command became XI Corps, Army of the Potomac in late 1862, the De Kalbs were in First Brigade of Stahel's First Division.

Von Gilsa warned the division commander, Charles Devens, that Confederate troops had been detected in the woods near his line.

[5] In June 1863, Von Gilsa initially had bad relations with the new division commander, Francis C. Barlow, who put him under arrest for allowing more than one man at a time to leave the column to get water.

Carroll's brigade joined the XI Corps soldiers in holding the line against any potential Confederate attack on the third day of the battle.

The veterans of the De Kalb Regiment returned to New York City in June 1864, with von Gilsa still in command.