ClubLocationLeagueTierFounded
SC Bad Tatzmannsdorf—II. Liga Süd - Burgenland—1923
SD San Pedro—División de Honor de Vizcaya—1923
SMUC—Régional 1 - Méditerranée—1923
Sabugy—Campeonato Paraibano - 2ª Divisão—1923Saint-Georges-les-Ancizes—Régional 3 - Auvergne-Rhône-Alpes—1923Salamanca—Dissolved 2013—1923
Salts—West Yorkshire League - Division Two—1923
Sambenedettese—Serie D - Girone F—1923Sambiase—Eccellenza Calabria—1923Sampaio Corrêa—Campeonato Maranhense - Série A—1923Sant Cugat—Primera Catalana—1923Schrems—Landesliga Niederösterreich—1923
Serp i Molot—Dissolved 2017—1923
Spartak Trnava—Fortuna Liga—1923
Spora—Dissolved 2005—1923
Sporting Barranquilla—Dissolved 1991—1923
Sporting Covilhã—Liga Portugal 3—1923
Sporting Lokeren—Dissolved 2020—1923
Sporting Praia—Primeira Divisão de Santiago Sul—1923Stade Brainois—Dissolved 2021—1923Stará Ľubovňa—II. Liga—1923
Suez Montakhab—Egyptian Second Division A—1923