The College of Staten Island is one of the "hybrid colleges" of the City University of New York. The college offers both associate's and bachelor's degrees, hence it is a "hybrid" of a traditional four-year college and a two-year community college. The College of Staten Island is one of four such hybrid colleges in the CUNY system.

It was established in 1976 from the merger of Richmond College (opened in 1965) and Staten Island Community College (opened 1956). Richmond College had been threatened with closure because of New York City's financial crisis, while the older school, because of its status as a community college, received state support. The merger was particularly logical since the community college offered two year degrees, while Richmond College was an "upper divisional" college (the third in the nation) that offered degrees to those in their third and fourth years of schooling.

The College of Staten Island has been located on the grounds of the former Willowbrook State School since 1993. It is the largest campus, in terms of physical size, in New York City. Before the relocation to Willowbrook, the college had a split campus, located at the former Staten Island Community College (in Sunnyside, on Todt Hill) and Richmond College (in St. George).

The first president of the college, Dr. Edmond Volpe, retired in 1994, and was succeeded by Dr. Marlene Springer.