| Name | Meaning | Gender | Origin |
| Sassy | Lively and spirited | Unisex | English |
| Sausage | Chopped meat stuffed into a prepared casing and cooked. | Unisex | English |
| Scabbers | | Unisex | Hebrew |
| Schnapps | Variety of strong liquor usually associated with Holland | Unisex | English |
| Scooter | One who goes suddenly and speedily. | Unisex | English |
| Shadow | Shadow | Unisex | English |
| Shandy | Variant Of Shaun From John. | Female | English |
| Sheba | Daughter of an oath | Female | Hebrew |
| Shelby | A place where willows grow | Female | American English |
| Shorty | Of less than average size | Unisex | English |
| Simba | Lion | Female | Swahili |
| Simpson | Listening | Unisex | Hebrew |
| Skye | Cloud | Male | Norse |
| Slim | Slender in proportion to height. | Unisex | English |
| Slinky | | Unisex | Hebrew |
| Snap | | Unisex | Hebrew |
| Snapper | | Unisex | Hebrew |
| Snickers | A brand of candy bar. | Unisex | English |
| Snuffles | | Unisex | Hebrew |
| Sophie | Wisdom | Female | Greek |
| Sparky | Animated, lively. | Unisex | English |
| Speckles | | Unisex | Hebrew |
| Spencer | Someone who gives out goods | Male | French |
| Spongebob | | Unisex | Hebrew |
| Squirt | Slang for a small person | Unisex | English |
| Stanley | Meadow that is stony | Male | English |
| Sterling | Little star - stellar | Male | English |
| Stormy | Violent weather | Unisex | English |
| Stretch | To extend to full length. | Unisex | English |
| Stumpy | A short, thickset person | Unisex | English |