| Name | Meaning | Gender | Origin |
|---|
| Prince | Royal son | Male | English |
| Rambo | | Unisex | Hebrew |
| Ranger | Gamekeeper | Male | English |
| Raven | Raven | Male | English |
| Riley | Rye clearing | Male | English |
| River | River | Unisex | English |
| Rogue | | Unisex | Hebrew |
| Rusty | Rusty, full of rust | Unisex | American English |
| Sable | Sable (black) | Unisex | English |
| Sabre | | Unisex | Hebrew |
| Sal | Saviour | Male | Italian |
| Sam | He is called god | Male | Hebrew |
| Sandy | Defending men | Male | Greek |
| Sarge | Noncommissioned Army or Air Force rank | Unisex | English |
| Sasha | Defending men | Unisex | Greek |
| Satan | The Devil and adversary of God | Unisex | English |
| Scooter | One who goes suddenly and speedily. | Unisex | English |
| Shadow | Shadow | Unisex | English |
| Shark | | Unisex | Hebrew |
| Skye | Cloud | Male | Norse |
| Spike | A long, thick sharp-pointed piece of wood or metal | Male | English |
| Stone | Stone | Male | English |
| Sunny | Filled with sunlight | Male | English |
| Tank | A large metal container. A heavily armed combat vehicle | Unisex | English |
| Terry | Ruler of the people | Unisex | Germanic |
| Tex | Of Texas | Unisex | English |
| Thunder | Stormy Tempered | Unisex | English |
| Tiger | Tiger | Unisex | English |
| Titan | Powerful big man | Unisex | Greek |
| Toby | God is good | Unisex | Hebrew |