| Name | Meaning | Gender | Origin |
|---|
| Rocko | | Unisex | Hebrew |
| Roo | | Unisex | Hebrew |
| Rugrat | | Unisex | Hebrew |
| Runt | | Unisex | Hebrew |
| Safari | | Unisex | Hebrew |
| Sam | He is called god | Male | Hebrew |
| Sandy | Defending men | Male | Greek |
| Satchel | Sack | Male | English |
| Sausage | Chopped meat stuffed into a prepared casing and cooked. | Unisex | English |
| Scooby | | Unisex | Hebrew |
| Scruff | | Unisex | Hebrew |
| Shadow | Shadow | Unisex | English |
| Shaggy | Bushy and matted (hair), unkempt. | Unisex | English |
| Skip | Master of a Ship | Male | American English |
| Sky | Sky | Unisex | Norse |
| Slipper | | Unisex | Hebrew |
| Smudge | A blotch or smear | Unisex | English |
| Sniff | A short inhale through the nose. To savour or investigate a smell. | Unisex | English |
| Snoopy | | Unisex | Hebrew |
| Snuffles | | Unisex | Hebrew |
| Socks | Short stockings finishing above the ankle | Unisex | English |
| Sparky | Animated, lively. | Unisex | English |
| Spike | A long, thick sharp-pointed piece of wood or metal | Male | English |
| Sprocket | | Unisex | Hebrew |
| Spunky | Spirited, plucky. | Unisex | English |
| Sputnik | | Unisex | Hebrew |
| Squeak | | Unisex | Hebrew |
| Stimpy | | Unisex | Hebrew |
| Strider | | Unisex | Hebrew |
| Terminator | | Unisex | Hebrew |