| Name | Meaning | Gender | Origin |
|---|
| Scamp | A mischievous youngster | Unisex | English |
| Scooby | | Unisex | Hebrew |
| Scooter | One who goes suddenly and speedily. | Unisex | English |
| Scout | Observer | Unisex | American English |
| Shadow | Shadow | Unisex | English |
| Shamus | Supplanter | Male | Hebrew |
| Shepherd | One who guards sheeps | Male | English |
| Sherman | One who shears cloth | Male | English |
| Shorty | Of less than average size | Unisex | English |
| Sigmund | Protector | Male | German |
| Simba | Lion | Female | Swahili |
| Skeeter | | Unisex | Hebrew |
| Skippy | Master of a Ship | Unisex | American English |
| Smokey | A grayish blue colour. Slang for highway patrol officer | Unisex | English |
| Snake | | Unisex | Hebrew |
| Snoopy | | Unisex | Hebrew |
| Snowball | | Unisex | Hebrew |
| Socks | Short stockings finishing above the ankle | Unisex | English |
| Soda | A carbonated water. | Unisex | English |
| Sparkey | | Unisex | Hebrew |
| Sparky | Animated, lively. | Unisex | English |
| Speed | Success | Unisex | English |
| Spencer | Someone who gives out goods | Male | French |
| Spike | A long, thick sharp-pointed piece of wood or metal | Male | English |
| Spot | After Data's cat on Star Trek: The Next Generation | Unisex | English |
| Squirt | Slang for a small person | Unisex | English |
| Stevie | Crown | Unisex | Greek |
| Stone | Stone | Male | English |
| Sylvester | A forest | Male | Latin |
| Taco | A folded fried tortilla filled with meat, cheese and spices. | Unisex | English |