The 125th New York Volunteer Infantry Regiment was a volunteer regiment from Rensselaer County, New York, during the American Civil War. Formed during the summer of 1862, the unit was officially mustered into United States Service on 27–29 August 1862, by Col. George L. Willard. He had seen previous service in the War of the Rebellion and in the Mexican War as well. Levin Crandall was commissioned lieutenant colonel, and James C. Bush major. The unit was mustered out on 5 June 1865.