| Name | Meaning | Gender | Origin |
|---|
| River | | Male | |
| Rogue | | Male | |
| Roman | citizen of Rome | Male | Latin |
| Rosebud | | Unisex | Hebrew |
| Rugby | rook fortress | Male | English |
| Rupert | middle name: Biggles | Male | |
| Sammy | Hebrew, told by God | Male | English |
| Samson | Bright sun
| Male | Hebrew |
| Sandy | Abbreviation of Alexander defender of man.
| Male | Scottish |
| Satan | The Devil and adversary of God | Male | |
| Saturn | Sixth and second largest planet away from the Sun. | Male | |
| Scout | One dispatched from main body to gather information | Male | Word |
| Sergeant | to serve | Male | Latin |
| Shark | | Unisex | |
| Sherbert | Frozen dessert made from fruit, sugar and water. Australian slang for beer. | Unisex | |
| Sherlock | Blond
| Male | English |
| Sigurd | Victorious Guardian | Unisex | Scandinavian |
| Silver | White
| Male | English |
| Slate | | Male | |
| Smoke | | Unisex | |
| Smoke | | Unisex | |
| Snuffles | | Unisex | Hebrew |
| Steel | Strong metal alloy made of iron and carbon. Hard unflinching character. | Male | Word |
| Storm | Storm
| Male | Word |
| Sumo | Form of wrestling. | Unisex | |