| Name | Meaning | Gender | Origin |
|---|
| Seymour | Moor | Male | Latin |
| Shadow | Shadow | Unisex | English |
| Shaggy | Bushy and matted (hair), unkempt. | Unisex | English |
| Shelly | Clearing near a ledge | Unisex | English |
| Sherman | One who shears cloth | Male | English |
| Shiloh | Gift for him | Unisex | Hebrew |
| Shorty | Of less than average size | Unisex | English |
| Sid | Wide meadow | Male | English |
| Skip | Master of a Ship | Male | American English |
| Skipper | Master of a Ship | Male | American English |
| Sleepy | | Unisex | Hebrew |
| Slinkster | | Unisex | Hebrew |
| Slinky | | Unisex | Hebrew |
| Smiley | | Unisex | Hebrew |
| Smokey | A grayish blue colour. Slang for highway patrol officer | Unisex | English |
| Smoky | | Unisex | Hebrew |
| Smudge | A blotch or smear | Unisex | English |
| Sneezy | | Unisex | Hebrew |
| Snicker | | Unisex | Hebrew |
| Sniff | A short inhale through the nose. To savour or investigate a smell. | Unisex | English |
| Snoopy | | Unisex | Hebrew |
| Snowball | | Unisex | Hebrew |
| Snuffles | | Unisex | Hebrew |
| Sonny | Son | Male | English |
| Sparky | Animated, lively. | Unisex | English |
| Speckles | | Unisex | Hebrew |
| Spencer | Someone who gives out goods | Male | French |
| Spike | A long, thick sharp-pointed piece of wood or metal | Male | English |
| Spot | After Data's cat on Star Trek: The Next Generation | Unisex | English |
| Sprocket | | Unisex | Hebrew |