| Name | Meaning | Gender | Origin |
|---|
| Rocky | rest | Male | English |
| Rootbeer | | Unisex | |
| Rusty | Covered in rust - a brownish red colour. | Unisex | |
| Sadie | Princess
| Female | English |
| Sam | to hear | Male | English |
| Samatha | God Has Heard | Unisex | English |
| Sarge | Noncommissioned Army or Air Force rank | Male | |
| Sasha | defending men | Female | Russian |
| Sassy | Lively and spirited | Female | |
| Sausage | Chopped meat stuffed into a prepared casing and cooked. | Unisex | |
| Scat Cat | | Unisex | |
| Schnapps | Variety of strong liquor usually associated with Holland | Unisex | |
| Scooter | One who goes suddenly and speedily. | Male | |
| Scrabble | | Unisex | |
| Scratchy | | Unisex | |
| Scruffy | Shabby or untidy | Unisex | |
| Sebastian | An august person | Male | Latin |
| Seymour | From St. Maur
| Male | English |
| Shadow | A rough, dark image cast by an object blocking the sun's rays | Female | English |
| Showoff | | Unisex | Hebrew |
| Shredder | | Unisex | Hebrew |
| Silence | | Female | Hebrew |
| Simba | lion | Male | Swahili |
| Simba | from The Lion King | Male | Swahili |
| Simon | he who hears | Male | Hebrew |