St. Paul's Co-educational College Alumni Association was first established in 1921 in the name of "聖 保 羅 舊 生 同 學 會" (at the time the School was called St. Paul's Girls' College).
The Association was expanded in 1930 with affiliated associations established in Shanghai and Canton, China. In 1938, the Association was re-organized and renamed as "聖 保 羅 校 友 會".
The Association's activities were suspended during World War II (that is, between December 1941 to August 1945) and from 1945 to 1946.
The Association resumed its activities after World War II in 1947 and changed its name to "St. Paul's College Alumni Association".
Following the name change of the School to St. Paul's Co-educational College in 1950, the Association was renamed as "St. Paul's Co-educational College Alumni Association".
The Association was incorporated under the Hong Kong Companies Ordinance as a non-profit organisation on 28 May 1965 under the name of "Saint Paul's Co-educational College Alumni Association Limited" ("聖 保 羅 男 女 中 學 校 友 會 有 限 公 司"). This remains the official name of the Association until now.
The Association's own office was first established in 1990. In view of the increased amount of activities conducted by the Association, the School Council had kindly allotted additional space at No. 1 Calder Path in 1995 for expansion of the Association's office.
The Association currently has the following affiliated associations established outside Hong Kong:-
St. Paul's Co-educational College Alumni Association British Columbia Chapter
St. Paul's Co-educational College Los Angeles Alumni Association
St. Paul's Co-educational College Alumni Association (New South Wales Chapter)
St. Paul's Co-educational College Alumni Association (New York Chapter)
St. Paul's Co-educational College Alumni Association (Ontario)
St. Paul's Co-educational College San Francisco Bay Area Alumni Association