| Shiela | A name meaning blind or wise. |
| Shields | Loyal protector |
| SHOLTO | One who is a royal seed |
| Shon | Feminine form of John: God is gracious. |
| Shoney | One who is full of grace |
| SIaibhin | A person who is truly fearless. |
| Sighle | Gaelic form of Sheila. |
| Silis | Gaelic form of Sheila. |
| Siolat | A name meaning a calm stream. |
| Sissy | Derived from cecilia |
| SIuaghan | A variant of the name Siobhn. |
| Skelley | Derived from a rocky island. |
| SKELLY | A name meaning rocky meadow. |
| Skyla | A name meaning a scholar or protector. |
| Slaven | One who brings great glory. |
| Slavin | One who is known for glory. |
| Sleven | A variation of the name Slevin. |
| SLEVIN | An Irish name meaning mountain. |
| Slevyn | A modern spelling of the name. |
| Slone | A name meaning a small mountain. |
| Somerled | A summer traveler or sailor |
| SOMHAIRLE | A summer wanderer or sailor |
| Sonnagh | A mound or rampart |
| Steaphan | Crown; wreath. Variant of Stephen. |
| STIABHAN | Gaelic form of Stephen (crowned) |
| TAGGART | son of a prelate |
| Taidhg | An ancient Irish name meaning poet. |
| TAITHLEACH | A name meaning quiet or peaceful soul. |
| Tara | From the crag of a tower.; Goddess of the sea.; A hill where the kings met; Where the kings met also Taras Halls were the place where ancient Bards sang deeds of Irish heroes. The ruins of the Halls are on the hill of Tara meaning crag or tower in Gaelic |
| Taran | Earth; Lord Vishnu; Raft, heaven; Of the thunder |
| Tarmon | A name meaning a sanctuary or refuge. |
| Teagan | Attractive; Good-looking.; A handsome man; One who is attractive; Ttractive,wise poet,philosopher,king. Derived from the male names Teague and Tadhg and the surname O'Tadhgain. Gaelic form of Timothy |
| Tearley | A name meaning from the meadow land. |
| Tearly | A name meaning a precious treasure. |
| Teimhnean | A Gaelic name meaning dark or dusky. |
| Tera | Derived from the Greek word for earth. |
| Teranika | Earth's victory |
| Tieve | An Irish name meaning a hillside. |
| TIOBOID | A variant of the name Theobald |
| TOIRDEALBACH | A name meaning a bold instigator. |