The 65th New York Infantry Regiment (or 1st United States Chasseurs) was an infantry regiment in the Union Army during the American Civil War.

The regiment wore distinctive chasseur styled uniforms.

The 65th New York Infantry was organized at the Fort at Willets Point, New York and mustered in for three years service beginning in July 1861 under the command of Colonel John Cochrane.

[1] The regiment was attached to Defenses of Washington to October 1861.

Graham's Brigade, Buell's Division, Army of the Potomac, to March 1862.

2nd Brigade, 1st Division, IV Corps, Army of the Potomac, to July 1862.

1st Brigade, 3rd Division, VI Corps, to April, 1864.

The regiment left New York for Washington, D.C., on August 27, 1861.

Movement to Stafford Court House, Va., October 20-November 18, and to Belle Plains December 5.

Duty at Brandy Station until January 1864, and at Johnson's Island, Lake Erie, Ohio, until March.

Jerusalem Plank Road, Hatcher's Run, June 22–23.

Repulse of Early's attack on Fort Stevens and the northern defenses of Washington July 11–12.

Sheridan's Shenandoah Valley Campaign August 6-November 28.

Dabney's Mills, Hatcher's Run, February 5–7, 1865.

The 65th New York Infantry mustered out of service July 17, 1865.

The regiment's wore a distinctive short chasseur jacket with extensive sky blue trim.