| Name | Meaning | Gender | Origin |
|---|
| Sasha | defending men | Female | Russian |
| Sassy | Lively and spirited | Female | |
| Scaredy | | Unisex | Hebrew |
| Scooter | One who goes suddenly and speedily. | Male | |
| Sebastian | An august person | Male | Latin |
| Shadow | A rough, dark image cast by an object blocking the sun's rays | Female | English |
| Sheba | from Sheba | Female | Hebrew |
| Simba | lion | Male | Swahili |
| Simba | from The Lion King | Male | Swahili |
| Simon | he who hears | Male | Hebrew |
| 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 | |
| Smudge | A blotch or smear | Male | |
| Snickers | A brand of candy bar. | Unisex | |
| Snickers | A brand of candy bar. | Unisex | |
| Snowball | | Unisex | |
| Snuggles | To curl up closely, cuddle | Male | |
| Snuggles | To curl up closely, cuddle | Male | |
| Socks | Short stockings finishing above the ankle | Unisex | |
| Sooty | Covered with soot | Unisex | |
| Sophie | Wisdom. Variant of Sophia
| Female | |
| Sox | Short stockings finishing above the ankle | Unisex | |
| Sox | Short stockings finishing above the ankle | Unisex | |
| Spooky | | Unisex | |