| Name | Meaning | Gender | Origin |
|---|
| Sparky | Animated, lively. | Unisex | English |
| Speed | Success | Unisex | English |
| Speedy | Rapid motion, swift. | Unisex | English |
| Spirit | Part of the human being associated with the mind. Vigorous or animated state - spirited. Also distilled alcohol. | Unisex | English |
| Spot | After Data's cat on Star Trek: The Next Generation | Unisex | English |
| Spud | Slang for potato. | Unisex | English |
| Spunky | Spirited, plucky. | Unisex | English |
| Squirt | Slang for a small person | Unisex | English |
| Stinky | | Unisex | Hebrew |
| Stormy | Violent weather | Unisex | English |
| Sundance | | Unisex | Hebrew |
| Sunday | 7th day of the week | Unisex | English |
| Sunshine | Light from the sun | Unisex | English |
| Sweetie | Sweetheart. | Unisex | English |
| Sweetie-pie | | Unisex | Hebrew |
| Taco | A folded fried tortilla filled with meat, cheese and spices. | Unisex | English |
| Tango | | Unisex | Hebrew |
| Tank | A large metal container. A heavily armed combat vehicle | Unisex | English |
| Taz | Wild Animal, Thrid Born | Unisex | American |
| T-bone | A thick steak containing a T shaped bone. | Unisex | English |
| Tequila | An alcoholic liquor distilled from mescal. | Unisex | English |
| Tex | Of Texas | Unisex | English |
| Thumper | To walk with heavy steps | Unisex | English |
| Thunder | Stormy Tempered | Unisex | English |
| Tiger | Tiger | Unisex | English |
| Tigger | From Winnie the Pooh | Unisex | English |
| Tiki | Maori figure representing an ancestor. A wooden or stone image of a Polynesian god. | Unisex | English |
| Tilly | Powerful battler | Unisex | Germanic |
| Timber | Wood used as a building material. Also timber-wolf. | Unisex | English |
| Tinker | | Unisex | Hebrew |