- Second Island
- Sedgwick
- Seguin Island
- Seguin Island
- Selden
- Sellers Island
- Sennetts Corner
- Septiemel Island
- Serag Island
- Seven Hundred Acre Island
- Seven Islands
- Seven Islands
- Sevenmile Island
- Shabbit Island
- Shabby Island
- Shady Nook
- Shag Island
- Shag Ledge
- Shag Ledge
- Shag Rock
- Shag Rock
- Shag Rock
- Shaker Village
- Shapleigh
- Shark Island
- Sharp
- Shaw Mills
- Shawmut
- Sheep Island
- Sheep Island