| Name | Meaning | Gender | Origin |
|---|
| Rogue | | Unisex | Hebrew |
| Rolo | Burmese | Unisex | English |
| Rufus | Red | Male | Latin |
| Sable | Sable (black) | Unisex | English |
| Sabre | | Unisex | Hebrew |
| Sammy | His name is God | Unisex | Hebrew |
| Sasha | Defending men | Unisex | Greek |
| Sasquatch | Has extra toes and hence is a bigfoot | Unisex | English |
| Satan | The Devil and adversary of God | Unisex | English |
| Saturn | Sixth and second largest planet away from the Sun. | Unisex | English |
| Skye | Cloud | Male | Norse |
| Socks | Short stockings finishing above the ankle | Unisex | English |
| Soda | A carbonated water. | Unisex | English |
| Sooty | Covered with soot | Unisex | English |
| Spike | A long, thick sharp-pointed piece of wood or metal | Male | English |
| Talon | A claw | Male | English |
| Tango | | Unisex | Hebrew |
| Tank | A large metal container. A heavily armed combat vehicle | Unisex | English |
| Tanner | Tanner | Male | English |
| Tex | Of Texas | Unisex | English |
| Thunder | Stormy Tempered | Unisex | English |
| Tilly | Powerful battler | Unisex | Germanic |
| Titan | Powerful big man | Unisex | Greek |
| Toby | God is good | Unisex | Hebrew |
| Trojan | | Unisex | Hebrew |
| Tyson | Son of Dye | Male | English |
| Ulysses | Walker | Male | Greek |
| Walden | Peasant's valley | Male | English |
| Wally | Ruler of the army | Male | Germanic |
| Will | Will, desire + helmet, protection | Male | Germanic |