| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 581 | Sheilah | Irish | Variant of Sheila: Irish variant of Celia: a Roman clan name. | F | |
| 582 | Shelagh | Irish | Variant of Sheila: Irish variant of Celia, from Celius, a Roman clan name. Also a form of Cecilia: blind. | F | |
| 583 | Siany | Irish | Good health. | F | |
| 584 | Sibeal | Irish | Prophetess. | F | |
| 585 | Sierra | Irish | Dark. Feminine of Ciaran. | F | |
| 586 | Sile | Irish | Youthful. | F | |
| 587 | Sine | Irish | Praise. | F | |
| 588 | Sinead | Irish | Gaelic form of Jane: God is gracious. Famous Bearer: singer Sinead O'Connor. | F | |
| 589 | Sineidin | Irish | Praise. | F | |
| 590 | Siobhan | Irish | Praise. Famous Bearer: actress Siobhan McKenna. | F | |
| 591 | Sive | Irish | Good. | F | |
| 592 | Slaine | Irish | Good health. | F | |
| 593 | Slany | Irish | Good health. | F | |
| 594 | Sorcha | Irish | Bright; intelligent. | F | |
| 595 | Sosanna | Irish | Lily. | F | |
| 596 | Sybil | Irish | Prophetess. | F | |
| 597 | Tara | Irish | Where the kings met. Also Tara's Halls, where ancient Bards sang deeds of Irish heroes. The ruins of the Halls are on the hill of Tara, meaning crag or tower. | F | |
| 598 | Tate | Irish | Measure of land. | F | |
| 599 | Tawnee | Irish | A green field; the warm sandy color of a lion's coat. | F | |
| 600 | Tawney | Irish | A green field; the warm sandy color of a lion's coat. | F | |