| Sacramento Knights | Continental Indoor Soccer League | — | 1993 | ARCO Arena |
| Sacramento Knights | National Premier Soccer League | — | 2003 | Folsom High School |
| Sacramento Republic FC | USL Championship | Sacramento | 3 December 2012 | Heart Health Park |
| Sacramento Surge | Major Arena Soccer League | — | 2012 | — |
| Saint Louis FC | USL Championship | St. Louis | 1 May 2014 | World Wide Technology Soccer Park |
| Salem City FC | USL League Two | Greensboro | 1993 | Macpherson Stadium |
| Salinas Valley Samba | National Premier Soccer League | — | 2004 | Watsonville High School |
| Salt Lake Sting | American Professional Soccer League | — | 1990 | Derks Field |
| San Antonio FC | USL Championship | — | 7 January 2016 | Toyota Field |
| San Antonio Pumas | — | — | 1988 | — |
| San Antonio Scorpions | North American Soccer League | — | 2010 | Toyota Field |
| San Diego 1904 FC | National Independent Soccer Association | San Diego | 2017 | Torero Stadium |
| San Diego FC | Major League Soccer | San Diego | 18 May 2023 | Snapdragon Stadium |
| San Diego Flash | A-League, National Premier Soccer League | San Diego | 1998 | Mira Mesa Senior High School |
| San Diego Gauchos | USL League Two | — | 2002 | Torero Stadium |
| San Diego Pumitas | National Premier Soccer League | — | 1999 | Balboa Stadium |
| San Diego Sockers | North American Soccer League | San Diego | 1978 | San Diego Stadium |
| San Diego Sockers | Major Arena Soccer League | San Diego | 2009 | Pechanga Arena |
| San Diego Sockers 2 | — | — | 2017 | Pechanga Arena |
| San Diego Spirit | Women's United Soccer Association | San Diego | 2001 | Torero Stadium |
| San Diego Surf | Premier Arena Soccer League | — | 1980 | — |
| San Diego Toros | North American Soccer League | San Diego | 1966 | Balboa Stadium |
| San Diego Zest FC | USL League Two | San Diego | 2016 | RIMAC Sports Complex |
| San Fernando Valley Quakes | USL League Two | Calabasas | 2006 | — |
| San Francisco Bay Blackhawks | — | — | 1989 | CEFCU Stadium |
| San Francisco Bay Diablos | — | San Francisco | 1993 | — |
| San Francisco City FC | USL League Two | San Francisco | 2001 | Negoesco Stadium |
| San Francisco Deltas | North American Soccer League | San Francisco | 2016 | Kezar Stadium |
| San Francisco Fog | — | — | 1980 | Cow Palace |
| San Francisco Glens | USL League Two | San Francisco | 1961 | Boxer Stadium |
| San Francisco Golden Gate Gales | — | San Francisco | 1967 | Candlestick Park |
| San Francisco Nighthawks | Women's Premier Soccer League | San Francisco | 1995 | Kezar Stadium |
| San Francisco Seals | A-League | San Francisco | 1992 | Negoesco Stadium |
| San Francisco Stompers FC | National Premier Soccer League | Hayward | 2012 | Pioneer Stadium |
| San Francisco Vikings Soccer Club | — | San Francisco | 1922 | — |
| San Gabriel Valley Highlanders | USL League Two | Glendale | 1997 | — |
| San Jose CyberRays | Women's United Soccer Association | San Jose | 2001 | CEFCU Stadium |
| San Jose Earthquakes | North American Soccer League | San Jose | 11 December 1973 | — |
| San Jose Earthquakes U23 | USL League Two | — | 2013 | — |
| San Jose Frogs | USL League Two | San Jose | 2005 | — |
| San Jose Grizzlies | Continental Indoor Soccer League | — | 1993 | SAP Center |
| San Juan United | Liga Nacional de Fútbol de Puerto Rico | — | 2008 | — |
| Santa Ana Winds FC | National Premier Soccer League | Santa Ana | 2009 | Santa Ana Stadium |
| Santa Barbara Condors | — | Santa Barbara | 1977 | — |
| Santa Barbara Sky FC | — | Santa Barbara | 2022 | — |
| Santa Cruz County Breakers | National Premier Soccer League | Santa Cruz | 2007 | — |
| Sarasota Paradise | USL League One | Lakewood Ranch | 19 November 2022 | — |
| Saturn FC | National Premier Soccer League | — | 2009 | — |