The 105th Infantry Regiment is an infantry regiment of the New York Army National Guard that saw combat in World War I and World War II. Originally, it was known as the 2nd New York Volunteer Infantry Regiment, but it was redesignated in 1916. The 105th fought as a part of the 27th Infantry Division during both World Wars, and was highly decorated for its actions during the Battle of Saipan, where its dogged defense against the largest Japanese Banzai charge of the war decimated its ranks, but prevented the American effort on the island from collapsing.

The New York Army National Guard is a component of the New York National Guard and the Army National Guard. Nationwide, the Army National Guard comprises approximately one half of the United States Army's available combat forces and approximately one third of its support organization. National coordination of various state National Guard units are maintained through the National Guard Bureau.