| Name | Meaning | Gender | Origin |
|---|
| Smiley | | Unisex | Hebrew |
| Snookums | | Unisex | Hebrew |
| Snoopy | | Unisex | Hebrew |
| Snowflake | Single flake or crystal of snow. | Unisex | English |
| Snuggles | To curl up closely, cuddle | Unisex | English |
| Sparkles | | Unisex | Hebrew |
| Sparky | Animated, lively. | Unisex | English |
| Special | | Unisex | Hebrew |
| Spirit | Part of the human being associated with the mind. Vigorous or animated state - spirited. Also distilled alcohol. | Unisex | English |
| Squirt | Slang for a small person | Unisex | English |
| Stinker | | Unisex | Hebrew |
| Sunday | 7th day of the week | Unisex | English |
| Sunny | Filled with sunlight | Male | English |
| Sunshine | Light from the sun | Unisex | English |
| Sweet | | Unisex | Hebrew |
| Sweetie | Sweetheart. | Unisex | English |
| Tarzan | White skin | Unisex | Literary |
| Teddy | Gift of God | Male | Greek |
| Tee | Tough | Male | Irish |
| Thaddeus | Uncertain, perhaps praised or heart | Male | Aramaic |
| Tickles | | Unisex | Hebrew |
| Tiger | Tiger | Unisex | English |
| Tink | | Unisex | Hebrew |
| Tinkerbell | | Unisex | Hebrew |
| Tootsie | A girl or young woman. | Unisex | English |
| Tulip | | Unisex | Hebrew |
| Turbo | Driven by a turbine - turbocharged | Unisex | English |
| Twinkie | A cream filled cake. | Unisex | English |
| Twinkle | | Unisex | Hebrew |
| Uri | My flame | Male | Hebrew |