| Name | Meaning | Gender | Origin |
|---|
| Smudge | A blotch or smear | Unisex | English |
| Sniff | A short inhale through the nose. To savour or investigate a smell. | Unisex | English |
| Sniffles | | Unisex | Hebrew |
| Snoopy | | Unisex | Hebrew |
| Snowy | Covered with snow | Female | English |
| Spanky | | Unisex | Hebrew |
| Sparky | Animated, lively. | Unisex | English |
| Speckles | | Unisex | Hebrew |
| Spike | A long, thick sharp-pointed piece of wood or metal | Male | English |
| Spirit | Part of the human being associated with the mind. Vigorous or animated state - spirited. Also distilled alcohol. | Unisex | English |
| Spooky | | Unisex | Hebrew |
| Sputnik | | Unisex | Hebrew |
| Squeaky | | Unisex | Hebrew |
| Squirt | Slang for a small person | Unisex | English |
| Stay | | Unisex | Hebrew |
| Sticky | | Unisex | Hebrew |
| Stinker | | Unisex | Hebrew |
| Stinky | | Unisex | Hebrew |
| Sully | Keen eye | Male | Gaelic |
| Sweetie | Sweetheart. | Unisex | English |
| Taco | A folded fried tortilla filled with meat, cheese and spices. | Unisex | English |
| Talli | Dew of God | Unisex | Hebrew |
| Tank | A large metal container. A heavily armed combat vehicle | Unisex | English |
| Taz | Wild Animal, Thrid Born | Unisex | American |
| Teaser | | Unisex | Hebrew |
| Tequila | An alcoholic liquor distilled from mescal. | Unisex | English |
| Tiger | Tiger | Unisex | English |
| Tiny | Extremely small | Unisex | English |
| Tizzy | | Unisex | Hebrew |
| Tootsie | A girl or young woman. | Unisex | English |