Formed in 1921, it is one of the oldest alumni in Singapore.  Membership is open to all Saints who have spent at least one full academic year in any of the 3 schools in St Andrew's.

The objectives of the Alumni are to foster a spirit of friendship and mutual co-operation among its members, to preserve the love of the Alma Mater, to mobilise support for and cooperate with the School and render whatever assistance that may from time to time be required for the benefit of the School, to maintain ties and uphold the “Spirit of the Saints” among former students of the School, to provide for sports, games, debates, lectures and other literary pursuits for the members, to initiate, assist and organise such forms of relief and schemes of social service as may be deemed desirable by the Alumni; and to bring about a better understanding and goodwill among all races living in Singapore.