- Salisbury (1,035 Companies)
- Salisbury Beach (1 Company)
- Sandisfield (45 Companies)
- Sandwich (1,347 Companies)
- Saugus (2,550 Companies)
- Savoy (28 Companies)
- Scituate (1,149 Companies)
- Seabrook (1 Company)
- Seekonk (1,811 Companies)
- Sharon (821 Companies)
- Sheffield (264 Companies)
- Shelburne Falls (397 Companies)
- Shelburne Fls (1 Company)
- Sheldonville (2 Companies)
- Sherborn (237 Companies)
- Shirley (363 Companies)
- Shrewsbury (2,465 Companies)
- Shutesbury (36 Companies)
- Siasconset (16 Companies)
- Silver Spring (1 Company)
- Somerset (1,115 Companies)
- Somerville (4,675 Companies)
- South Attleboro (36 Companies)
- South Barre (10 Companies)
- South Boston (1,879 Companies)
- South Carver (2 Companies)
- South Chatham (131 Companies)
- South Dartmouth (663 Companies)
- South Deerfield (576 Companies)
- South Dennis (764 Companies)
- South Easton (1,246 Companies)
- South Egremont (34 Companies)
- South Grafton (155 Companies)
- South Hadley (955 Companies)
- South Hamilton (427 Companies)
- South Harwich (2 Companies)
- South Lancaster (5 Companies)
- South Lee (2 Companies)
- South Orleans (6 Companies)
- South Walpole (22 Companies)
- South Waltham (1 Company)
- South Wellfleet (3 Companies)
- South Weymouth (1,159 Companies)
- South Yarmouth (1,086 Companies)
- Southampton (315 Companies)
- Southboro (4 Companies)
- Southborough (903 Companies)
- Southbridge (1,252 Companies)
- Southfield (18 Companies)
- Southwick (674 Companies)
- Spencer (741 Companies)
- Springfield (11,174 Companies)
- Sterling (547 Companies)
- Stockbridge (165 Companies)
- Stoneham (1,897 Companies)
- Stoughton (2,979 Companies)
- Stow (425 Companies)
- Sturbridge (765 Companies)
- Sudbury (1,427 Companies)
- Sunderland (170 Companies)
- Sutton (595 Companies)
- Swampscott (961 Companies)
- Swansea (1,389 Companies)
- Taunton (3,801 Companies)
- Teaticket (27 Companies)
- Templeton (183 Companies)
- Tewksbury (2,263 Companies)
- Thorndike (21 Companies)
