| Name | Meaning | Gender | Origin |
|---|
| Snoopy | | Male | |
| Snowball | | Unisex | |
| Snowflake | Single flake or crystal of snow. | Unisex | |
| Snowy | Covered with snow | Unisex | |
| Snuggles | To curl up closely, cuddle | Male | |
| Snuggles | To curl up closely, cuddle | Male | |
| Socks | Short stockings finishing above the ankle | Unisex | |
| Sonny | A boy or young man. | Male | Nickname |
| Sophia | Wisdom.
| Female | Greek |
| Sophie | Wisdom. Variant of Sophia
| Female | |
| Sox | Short stockings finishing above the ankle | Unisex | |
| Sox | Short stockings finishing above the ankle | Unisex | |
| Spanky | | Unisex | |
| Sparky | Animated, lively. | Unisex | |
| Sparta | | Unisex | |
| Spaz | For a spazy kitty
| Male | |
| Speedy | Rapid motion, swift. | Unisex | |
| Spencer | Shopkeeper, dispenser, keeper | Male | English |
| Spike | A long, thick sharp-pointed piece of wood or metal | Male | American |
| Spirit | Part of the human being associated with the mind. Vigorous or animated state - spirited. Also distilled alcohol. | Female | Word |
| Spooky | | Unisex | |
| Squeak | | Unisex | |
| Squiggle | | Unisex | |
| Stanley | Lives by the stony grove
| Male | English |
| Star | A celestial body that emits light. A famous performer. | Female | Word |