On October 10th, 1946 Mrs. Alicia Pearl Mayer initiated a meeting which was held at noon in the U.S. Grant Hotel for the purpose of forming the San Diego Genealogical Society. Her intention was to organize a society "for mutual help in the pursuance of genealogical work and for the establishing of a genealogical library for the benefit of members."

The San Diego Genealogical Society has come a long way since 1946 when its research collection consisted of two books and a number of manuscripts and pamphlets.  It began as a circulating collection exchanged at Society meetings. In January 1950 the collection was placed in a studio in the Spanish Village Art Center (built in 1935 for the California Pacific International Exposition) in Balboa Park. By 1957 there were 244 books in the library and the Society had yearly subscriptions to ten genealogy periodicals (journals, quarterlies, newsletters, etc.). By 1972 the collection had grown to more than 1,000 volumes. In June 1979 the SDGS library of about 3,000 volumes and 45 periodicals was moved to an apartment (leased from members Win and Edwina Goddard) on Point Loma. The genealogical collection outgrew this facility and moved to a house on Kalmia Street (also leased from Mr. and Mrs. Goddard) in the North Park neighborhood in October 1986. In October 1994 the library was moved to Pioneer Way in El Cajon. The library again outgrew its quarters and in 2009 moved to its present location at 7343 Ronson Road, Suite O, in San Diego. It is a secure facility with easy access and plenty of parking.

The San Diego Genealogical Society Newsletter has been published since 1963. This exceptional Newsletter is published and distributed monthly (except January) to all current members. The Newsletter contains information on upcoming meetings, speakers, seminars, research trips, fundraising events, special projects, library acquisitions, member research queries and other items of current interest to genealogists.

Since 1972 the San Diego Genealogical Society has published San Diego Leaves & Saplings, a quarterly publication of San Diego County, California historical and genealogical records. In its 36th volume, San Diego Leaves & Saplings has published cemetery, census, church, hospital, land, mortuary, school census, voter registration and numerous other records of interest and value to genealogists and family historians researching their San Diego County, California ancestry.

In 1995, SDGS hosted the National Genealogical Society's 'Conference in the States.' This four day event was attended by approximately 2,000 people from around the world. The Society hosted a series of Genealogical and Family History Fairs at the Scottish Rite Center beginning in 1996. SDGS was also host to GenTech 2000, two days of computer genealogy education for nearly 700 attendees.