| Name | Meaning | Gender | Origin |
|---|
| Rufus | Red | Male | Latin |
| Russel | Little red one | Male | French |
| Russell | Little red one | Male | French |
| Rusty | Rusty, full of rust | Unisex | American English |
| Saber | Patient | Male | English |
| Salem | Secure, peace | Unisex | Arabic |
| Sam | He is called god | Male | Hebrew |
| Sammy | His name is God | Unisex | Hebrew |
| Sandy | Defending men | Male | Greek |
| Sasha | Defending men | Unisex | Greek |
| Sassy | Lively and spirited | Unisex | English |
| Scooby | | Unisex | Hebrew |
| Scooter | One who goes suddenly and speedily. | Unisex | English |
| Scout | Observer | Unisex | American English |
| Seamus | Form Of James Supplanter. | Male | English |
| Seiko | Sincere child | Unisex | Japanese |
| Semolina | | Unisex | Hebrew |
| Seymour | Moor | Male | Latin |
| Shadow | Shadow | Unisex | English |
| Shakespeare | Brandish spear | Unisex | English |
| Shea | Hawklike - graceful, free, courageous | Male | Gaelic |
| Shilo | Gift for him | Unisex | Hebrew |
| Shiloh | Gift for him | Unisex | Hebrew |
| Shorty | Of less than average size | Unisex | English |
| Silas | Of the forest | Male | Latin |
| Silk | | Unisex | Hebrew |
| Sinclair | Saint Clair meaning holy light | Male | English |
| Skye | Cloud | Male | Norse |
| Skyler | Guarded | Unisex | Dutch |
| Slim | Slender in proportion to height. | Unisex | English |