St. Francis Xavier High School, 30 West 16th Street, ca. 1928.

Founded in 1847 by Father John Larkin, a professor at St. John's College (now Fordham University), the school was originally known as the College of St. Francis Xavier and offered instruction to boys from the ages eight to twenty-one.

A military training operation began at Xavier High School in 1886 under the direction of the National Guard; membership became mandatory in 1892. In the years that followed, collegiate and secondary studies were separated, and the college level department at the school closed in 1912.

From 1935 to 1968, Xavier High School acted as a Junior ROTC unit. Students took four years of military science and training, which was recognized upon enrollment in any branch of the United States Military. After 1971, participation in military studies was no longer mandatory.

Today, Xavier High School is an independent Jesuit university-preparatory high school for boys. Since 1928, when the school was first accredited, Xavier High School has held membership in the Jesuit Schools Network, the National Catholic Education Association, and the New York State Association of Independent Schools.