| Name | Meaning | Gender | Origin |
|---|
| Shadow | Shadow | Unisex | English |
| Shamus | Supplanter | Male | Hebrew |
| Shorty | Of less than average size | Unisex | English |
| Skeezix | | Unisex | Hebrew |
| Skip | Master of a Ship | Male | American English |
| Skippy | Master of a Ship | Unisex | American English |
| Skittles | | Unisex | Hebrew |
| Skye | Cloud | Male | Norse |
| Slim | Slender in proportion to height. | Unisex | English |
| Sly | A forest | Unisex | Latin |
| Snickers | A brand of candy bar. | Unisex | English |
| Snoopy | | Unisex | Hebrew |
| Snowball | | Unisex | Hebrew |
| Sparkey | | Unisex | Hebrew |
| Sparky | Animated, lively. | Unisex | English |
| Spencer | Someone who gives out goods | Male | French |
| Spike | A long, thick sharp-pointed piece of wood or metal | Male | English |
| Spunky | Spirited, plucky. | Unisex | English |
| Squirt | Slang for a small person | Unisex | English |
| Stephen | Crown | Male | Greek |
| Stumpy | A short, thickset person | Unisex | English |
| Sweetie | Sweetheart. | Unisex | English |
| Sylvester | A forest | Male | Latin |
| Taco | A folded fried tortilla filled with meat, cheese and spices. | Unisex | English |
| Tahoe | Edge of the lake | Unisex | Native American |
| Taj | Crown | Male | Sanskrit |
| Tank | A large metal container. A heavily armed combat vehicle | Unisex | English |
| Teddy | Gift of God | Male | Greek |
| Tequila | An alcoholic liquor distilled from mescal. | Unisex | English |
| Terence | Uncertain | Male | Latin |