Over time, additional schools were established in Salonica, including the Şemsi Efendi School, which was attended by Mustafa Kemal Atatürk.After the Balkan Wars, when Salonica became part of Greece, the foundation relocated to Nişantaşı Naciye Sultan Mansion in Istanbul.

In 1935, during the 50th anniversary of the school, the name was changed from "Feyziye" to "Işık," both meaning "light" in Turkish, with the endorsement of Mustafa Kemal Atatürk.

To address the increasing demand for educational institutions, the foundation completed its Maslak campus in 1996.

Işık University was established at the Maslak campus at the beginning of the 1996–1997 academic year, marking a new chapter in the foundation's history.

In 2005 summer, most of the university's academic and administrative departments (including the rector) moved to the Şile campus.