John Calvin Fiser (May 4, 1838 – June 4, 14, or 15, 1876) was an American merchant and soldier. He served as an officer in the Confederate Army during the American Civil War, fighting in both the Eastern as well as the Western theaters. Fiser was seriously wounded five times in the conflict, losing an arm in 1863's Battle of Fort Sanders, and he was appointed a general officer late in the war; however, the appointment was never confirmed by the Confederate Senate. Afterward he returned to his business interests and was active in Confederate veterans organizations.