Places beginning with SO in Maine, United States
- Sodom
- Sodom
- Soldier Pond
- Soldiertown, Township of
- Solon
- Solon, Town of
- Somers Corner
- Somerset County
- Somerset Junction
- Somerville
- Somerville, Town of
- Somesville
- Songo Lock
- Sorrento
- Sorrento, Town of
- Soule Mill
- South Acton
- South Addison
- South Albion
- South Amity
- South Andover
- South Arm
- South Aroostook, Unorganized Territory of
- South Bancroft
- South Berwick
- South Berwick, Town of
- South Blue Hill
- South Brewer
- South Bridgton
- South Bristol
- South Bristol, Town of
- South Brooksville
- South Buxton
- South Casco
- South China
- South Corinth
- South Cushing
- South Deer Isle
- South Dover
- South Dresden
- South Durham
- Southeast Piscataquis, Unorganized Territory of
- South Effingham
- South Eliot
- South Exeter
- South Franklin, Unorganized Territory of
- South Freeport
- South Gardiner
- South Gorham
- South Gouldsboro
- South Gray
- South Hancock
- South Harpswell
- South Hiram
- South Hollis
- South Hope
- South Jefferson
- South Lagrange
- South Lebanon
- South Leeds
- South Levant
- South Lewiston
- South Liberty
- South Limington
- South Lincoln
- South Livermore
- South Lubec
- South Monmouth
- South Montville
- South Naples
- South Newburgh
- South Newcastle
- South Orland
- South Orrington
- South Oxford, Unorganized Territory of
- South Paris
- South Parsonsfield
- South Penobscot
- South Poland
- Southport
- South Portland
- South Portland, City of
- South Portland Gardens
- Southport, Town of
- South Princeton
- South Rangeley
- South Robbinston
- South Rumford
- South Sanford
- South Sebec
- South Side
- South Solon
- South Springfield
- South Strong
- South Surry
- South Thomaston
- South Thomaston, Town of
- South Trescott
- South Turner
- South Union
- South Vassalboro
- South Waldoboro
- South Warren
- South Waterford
- South West Bend
- Southwest Harbor
- Southwest Harbor, Town of
- South Windham
- South Windsor
- South Woodstock
- South Woodville