The SCGS Alumni was formed in 1978 to provide the link between the old girls and the School. One of the objectives of the Alumni is to ensure that the values and mission of the School stay with the girls after they have left the school. The Alumni serves as a bridge to connect old girls to SCGS by keeping them in touch with the activities and events that are taking place within the School.

The Alumni stresses the importance of a continual relationship between an SCGS student and her alma mater after graduation, so as to give back what the teachers (who would have become friends following close interaction through the years) had taught and provided her during her terms there. With the Alumni getting increasingly involved in school activities, it is hoped that each girl will continue their friendship / relationship with the School. Students who have graduated from secondary 4 are strongly encouraged to join the Alumni and participate in its activities.

Over the last few years, besides encouraging Kim Geks to connect and network with each other, the Alumni has also been actively involved in projects to assist the School. These include helping the school in its fund-raising efforts to build the new wing for the primary school as well as the new sports complex.