- Shell Knob, Missouri
- Shelter Island, New York
- Sheridan, Colorado
- Short Hills, New Jersey
- Shreveport, Louisiana
- Sidman, Pennsylvania
- Siloam Springs, Arkansas
- Silver City, New Mexico
- Silverton, Oregon
- Skokie, Illinois
- Slaughters, Kentucky
- Slippery Rock, Pennsylvania
- Smithfield, North Carolina
- Smithfield, Virginia
- Smithville, Tennessee
- Smyrna, Delaware
- Smyrna, Georgia
- Snowmass, Colorado
- Snyder, Texas
- Solon, Ohio
- Somerset County, New Jersey
- Somerset, Kentucky
- Somerset, Pennsylvania
- Somerville, Massachusetts
- Somerville, Tennessee
- South Charleston, West Virginia
- South Chesterfield, Virginia
- South Gate, California
- South Haven, Michigan
- South Holland, Illinois
- South Kingstown, Rhode Island
- South Norwalk, Connecticut
- South Padre Island, Texas
- South Salt Lake, Utah
- South Sioux City, Nebraska
- Southampton, New York
- Southaven, Mississippi
- Southborough, Massachusetts
- Southlake, Texas
- Sparks, Nevada
