| Name | Meaning | Gender | Origin |
| Skippy | Master of a Ship | Unisex | American English |
| Skittles | | Unisex | Hebrew |
| Sky | Sky | Unisex | Norse |
| Skye | Cloud | Male | Norse |
| Skyler | Guarded | Unisex | Dutch |
| Slinky | | Unisex | Hebrew |
| Sly | A forest | Unisex | Latin |
| Smokey | A grayish blue colour. Slang for highway patrol officer | Unisex | English |
| Smudge | A blotch or smear | Unisex | English |
| Snickers | A brand of candy bar. | Unisex | English |
| Snoop | To pry into the private affairs of others | Unisex | English |
| Snoopy | | Unisex | Hebrew |
| Snowball | | Unisex | Hebrew |
| Snowflake | Single flake or crystal of snow. | Unisex | English |
| Snowy | Covered with snow | Female | English |
| Snuffles | | Unisex | Hebrew |
| Snuggles | To curl up closely, cuddle | Unisex | English |
| Solomon | Peace | Male | Hebrew |
| Sonny | Son | Male | English |
| Sophia | Wisdom | Female | Greek |
| Sophie | Wisdom | Female | Greek |
| Spanky | | Unisex | Hebrew |
| Sparkle | To shine with animation | Unisex | English |
| Sparky | Animated, lively. | Unisex | English |
| Speed | Success | Unisex | English |
| Speedy | Rapid motion, swift. | Unisex | English |
| Spencer | Someone who gives out goods | Male | French |
| 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 |
| Spot | After Data's cat on Star Trek: The Next Generation | Unisex | English |