| A.A.C. Eagles | United States Adult Soccer Association | Chicago | 1940 | — |
| AC Connecticut | USL League Two | Newtown | 2011 | — |
| AC Crusaders | National Premier Soccer League | — | 2010 | Egg Harbor Township High School |
| Academia Quintana | Puerto Rico Soccer League | — | 1969 | Hiram Bithorn Stadium |
| Adirondack Lynx | Women's Premier Soccer League | — | 2005 | — |
| Aegean Hawks | United States Adult Soccer Association | — | 1996 | — |
| AFC Ann Arbor | National Premier Soccer League | Ann Arbor | 2014 | — |
| AFC Cleveland | National Premier Soccer League | Independence | November 11, 2011 | Independence High School |
| AFC Lancaster Lions | American Soccer League | — | 2015 | Ephrata High School |
| Ajax Orlando Prospects | USL League Two | Orlando | 2002 | Warden Stadium |
| Akron Summit Assault | USL League Two | — | 2010 | St. Vincent–St. Mary High School |
| Alaska Timbers | United Premier Soccer League | Anchorage | — | — |
| Albany BWP Highlanders | USL League Two | — | 2003 | — |
| Albion SC San Diego | National Premier Soccer League | San Diego | 2015 | Mission Bay High School |
| Albuquerque Asylum | National Premier Soccer League | — | 2004 | Menaul School |
| Anaheim Splash | Continental Indoor Soccer League | — | 1992 | Honda Center |
| Arizona Impact | Premier Arena Soccer League | — | 2013 | — |
| Arizona Rush | Women's Premier Soccer League | Arizona | 2007 | — |
| Arizona Sandsharks | Continental Indoor Soccer League | Arizona | 1992 | Mortgage Matchup Center |
| Arizona Storm | Major Arena Soccer League | Arizona | 2011 | — |
| Arizona Thunder | World Indoor Soccer League | Arizona | 1998 | Arizona Veterans Memorial Coliseum |
| Arlington Aviators | Western Indoor Soccer League | — | 2012 | — |
| Asheville City SC | National Premier Soccer League | Asheville | 2016 | Memorial Stadium, Asheville |
| Athletic Club Boise | — | Garden City | 2024 | — |
| Atlanta Beat | Women's Professional Soccer | Atlanta | 2010 | Fifth Third Stadium |
| Atlanta Beat | Women's United Soccer Association | Atlanta | 2001 | Herndon Stadium |
| Atlanta Blackhawks | USL League Two | — | 2009 | Alpharetta High School |
| Atlanta Chiefs | National Professional Soccer League | Atlanta | 1967 | Atlanta-Fulton County Stadium |
| Atlanta City FC | National Women's Soccer League | Atlanta | — | Mercedes-Benz Stadium |
| Atlanta Silverbacks | North American Soccer League, A-League | Atlanta | 1994 | Atlanta Silverbacks Park |
| Atlanta Silverbacks Reserves | National Premier Soccer League | Atlanta | 2007 | Atlanta Silverbacks Park |
| Atlanta Silverbacks U23's | USL League Two | — | 2006 | Atlanta Silverbacks Park |
| Atlantic City Diablos | National Premier Soccer League | — | 2007 | St. Augustine College Preparatory School |
| Atletico Baja | Major Arena Soccer League | — | 2015 | — |
| Atlético Dallas | USL Championship | Dallas | 2024 | — |
| Atlético de San Juan FC | Puerto Rico Soccer League | San Juan | 2008 | Hiram Bithorn Stadium |
| Atléticos de Levittown FC | Puerto Rico Soccer League | — | 1989 | — |
| Augusta FireBall | USL League Two | — | 2005 | Patriots Park |
| Austin Aztex | USL Championship, USL League Two | Austin | 2011 | House Park |
| Austin Aztex FC | USSF Division 2 Professional League | Austin | 2008 | House Park |
| Austin Aztex U23 | USL League Two | — | 2007 | Round Rock High School |
| Austin Bold FC | USL Championship | Austin | August 9, 2017 | Bold Stadium |
| Austin FC | Major League Soccer | Austin | 2018 | Q2 Stadium |
| Austin Lone Stars | — | Austin | 1987 | — |