| Name | Meaning | Gender | Origin |
|---|
| Sandy | Defending men | Male | Greek |
| Santa | Saintlike | Unisex | Spanish |
| Satan | The Devil and adversary of God | Unisex | English |
| Satchel | Sack | Male | English |
| Scamp | A mischievous youngster | Unisex | English |
| Scamper | | Unisex | Hebrew |
| Scout | Observer | Unisex | American English |
| Scuttle | | Unisex | Hebrew |
| Sea | Mercy in god | Unisex | Hebrew |
| Sebastian | Man from Sebaste | Male | Latin |
| Serena | Composed | Female | Latin |
| Seymore | Our cat who likes to hide that we want to see more of | Unisex | English |
| Seymour | Moor | Male | Latin |
| Shadow | Shadow | Unisex | English |
| Shaggy | Bushy and matted (hair), unkempt. | Unisex | English |
| Shelby | A place where willows grow | Female | American 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 |
| Sid | Wide meadow | Male | English |
| Skip | Master of a Ship | Male | American English |
| Skipper | Master of a Ship | Male | American English |
| Skylar | Guarded | Female | Dutch |
| Sleepy | | Unisex | Hebrew |
| Slinkster | | Unisex | Hebrew |
| Slinky | | Unisex | Hebrew |
| Smiley | | Unisex | Hebrew |
| Smokey | A grayish blue colour. Slang for highway patrol officer | Unisex | English |
| Smoky | | Unisex | Hebrew |