The CIF San Diego Section (CIF-SDS) is the governing body of high school athletics for most of the two southernmost counties of California (San Diego and Imperial Counties), one of ten such sections that comprise the California Interscholastic Federation (CIF).

Its membership includes most public and private high schools in San Diego and Imperial counties.

Official governance for high school sports in this area began in 1913, when the Southern California Interscholastic Athletic Council (SCIAC) was formed.

In 2000, Imperial County split from Southern Section and joined with San Diego.

In 2013 the section began organizing playoff divisions based on team strength not school enrollment.