| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 801 | Rory | Gaelic | Red; ruddy. | M | |
| 802 | Ros | Gaelic | Rose. | F | |
| 803 | Rourke | Gaelic | An ancient given name adopted as an Irish clan name. Surname. | M | |
| 804 | Rowan | Gaelic | Red. Rowan tree (a type of ash tree). Famous Bearer: actor Rowan Atkinson. | M | |
| 805 | Roy | Gaelic | Red. | M | |
| 806 | Royal | Gaelic | Red. | M | |
| 807 | Royall | Gaelic | Red. | M | |
| 808 | Royan | Gaelic | Red-haired; red. | M | |
| 809 | Ruailidh | Gaelic | Famous ruler. | M | |
| 810 | Ruanaidh | Gaelic | Red haired. | M | |
| 811 | Ryan | Gaelic | Little king. | M | |
| 812 | Scully | Gaelic | Town crier. | M | |
| 813 | Seamus | Gaelic | Form of James. Supplanter. | M | |
| 814 | Seana | Gaelic | Gift from God. | F | |
| 815 | Seonaid | Gaelic | Gift from God. | F | |
| 816 | Seorus | Gaelic | Farmer. | M | |
| 817 | Seosamh | Gaelic | He shall add. | M | |
| 818 | Seumas | Gaelic | Supplanter. | M | |
| 819 | Sguelaiche | Gaelic | Storyteller. | M | |
| 820 | Shan | Gaelic | old; wise. | M | |