| Name | Meaning | Gender | Origin |
|---|
| Sebastian | Man from Sebaste | Male | Latin |
| Shadow | Shadow | Unisex | English |
| Shady | | Unisex | Hebrew |
| Shaggy | Bushy and matted (hair), unkempt. | Unisex | English |
| Shelly | Clearing near a ledge | Unisex | English |
| Sherman | One who shears cloth | Male | English |
| Shiloh | Gift for him | Unisex | Hebrew |
| Shorty | Of less than average size | Unisex | English |
| Silky | Soft as silk. | Unisex | English |
| Silver | Silver (the metal or colour) | Male | English |
| Silvester | A forest | Male | Latin |
| Simon | Listening | Male | Hebrew |
| Skeeter | | Unisex | Hebrew |
| Skinny | | Unisex | Hebrew |
| Skip | Master of a Ship | Male | American English |
| Skipper | Master of a Ship | Male | American English |
| Skippy | Master of a Ship | Unisex | American English |
| Skittles | | Unisex | Hebrew |
| Sky | Sky | Unisex | Norse |
| Skye | Cloud | Male | Norse |
| Skyler | Guarded | Unisex | Dutch |
| Slinky | | Unisex | Hebrew |
| Sly | A forest | Unisex | Latin |
| Smokey | A grayish blue colour. Slang for highway patrol officer | Unisex | English |
| Smudge | A blotch or smear | Unisex | English |
| Snickers | A brand of candy bar. | Unisex | English |
| Snoop | To pry into the private affairs of others | Unisex | English |
| Snoopy | | Unisex | Hebrew |
| Snowball | | Unisex | Hebrew |
| Snowflake | Single flake or crystal of snow. | Unisex | English |