| Name | Meaning | Gender | Origin |
|---|
| Sluggo | | Male | |
| Smoke | | Unisex | |
| Smoke | | Unisex | |
| Smokey | A grayish blue colour. Slang for highway patrol officer | Male | |
| Smokey | A grayish blue colour. Slang for highway patrol officer | Male | |
| Smokey | A grayish blue colour. Slang for highway patrol officer | Male | |
| Smoky | | Unisex | |
| Smudge | A blotch or smear | Male | |
| Snowdrop | | Male | |
| Snuggles | To curl up closely, cuddle | Male | |
| Snuggles | To curl up closely, cuddle | Male | |
| Sombra | Spanish for shadow | Unisex | |
| Sooty | Covered with soot | Unisex | |
| Sparkles | | Unisex | |
| Speck | | Male | Hebrew |
| Spirit | Part of the human being associated with the mind. Vigorous or animated state - spirited. Also distilled alcohol. | Female | Word |
| Spooky | | Unisex | |
| Spunky | Spirited, plucky. | Male | |
| Stardust | | Female | |
| Steel | Strong metal alloy made of iron and carbon. Hard unflinching character. | Male | Word |
| Steel Wool | | Unisex | |
| Sterling | British money or coin. A type of silver. Of good character. genuine, valued | Male | English |
| Stitches | | Male | Hebrew |
| Stoney | Stone-Lie | Unisex | Greek |
| Storm | Storm
| Male | Word |