- South Warren
- Southern Mark Island
- Sparrow Island
- Spaulding Island
- Spectacle Island
- Spectacle Island
- Spectacle Island
- Spectacles
- Sprucehead Island
- Stickney Corner
- Stimpsons Island
- Stoddart Island
- Stone Island
- Stovers Corner
- Sand Island
- Sheep Island
- Shelter Island
- Slab City
- Smith Crossing
- Sodom
- South Andover
- South Arm
- South Hiram
- South Rumford
- South Woodstock
- Spirt Island
- Spurrs Corner
- Squirrel Island
- Stevens Island
- Stoneham