The LaSalle Center, operated by the De La Salle Christian Brothers, became the Oakdale campus of St. John's University at a Signing Ceremony on July 8, 1999. Several graduate programs were soon featured there, including library and information science, criminal justice leadership, school psychology, and educational administration and supervision. The 175-acre campus was the former estate of Frederick Bourne, overlooking the Great South Bay. In 1926, it became the home of the La Salle Military Academy, Preparatory Academy, Middle School, and Primary School. On September 27, 2016, the sale of the Oakdale campus was announced.
On August 17, 2017, one year after the announcement of the sale of the Oakdale campus, the new Long Island Graduate Center at 120 Commerce Drive, Hauppauge, New York, was dedicated.
College Europa was the first study abroad program at St. John’s University, launched in 1985. The program was centered in Budapest, Hungary, but students also traveled to several other countries during their time in the program. Study Abroad Ireland began in September 1992 and Study Abroad Japan began in September 1993. Since then, many other study abroad options were made available.
In 1995, a Rome Graduate Center was established at Via Santa Maria Mediatrice 24, in Rome, Italy.
On October 12, 2008, a blessing and dedication ceremony was held at the new Rome Graduate Center at Via Marcantonio Colonna 21A, in Rome, Italy.
In 2008, a Study Center was opened at 93, rue de Sèvres, in Paris, France, in 2008.