| Name | Meaning | Gender | Origin |
|---|
| Riley | Rye clearing | Male | English |
| Ringo | Apple, peace be with you | Male | English |
| River | River | Unisex | English |
| Rock | Stone | Male | English |
| Rocket | To move swiftly and powerfully | Unisex | English |
| Rocky | Battle cry | Male | Germanic |
| Rosco | Roe deer wood | Unisex | Norse |
| Ruby | Red | Female | Latin |
| Rue | Fame | Female | German |
| Sam | He is called god | Male | Hebrew |
| Samson | Sun | Male | Hebrew |
| Sarge | Noncommissioned Army or Air Force rank | Unisex | English |
| Sargent | A Squire | Male | English |
| Scout | Observer | Unisex | American English |
| Shiloh | Gift for him | Unisex | Hebrew |
| Sid | Wide meadow | Male | English |
| Sky | Sky | Unisex | Norse |
| Sniff | A short inhale through the nose. To savour or investigate a smell. | Unisex | English |
| Sniper | A skilled shooter who spots targets from a concealed place. | Unisex | English |
| Sonny | Son | Male | English |
| Spade | | Unisex | Hebrew |
| Sparkey | | Unisex | Hebrew |
| Speedy | Rapid motion, swift. | Unisex | English |
| Spike | A long, thick sharp-pointed piece of wood or metal | Male | English |
| Stan | Meadow that is stony | Male | English |
| Stetson | Son of Stephen | Male | English |
| Stone | Stone | Male | English |
| Storm | Violent weather | Female | English |
| Suzy | Lily | Female | Hebrew |
| Tab | Brilliant | Male | English |