| DITTE f Danish |
| DODIE f English |
| DOLLIE f English |
| DOLLY f English |
| DÓRA f Hungarian |
| DORA f English, Dutch, Spanish, Greek, Croatian, Serbian |
| DOREEN f English |
| DORETE f Danish |
| DORETTA f English |
| DORIA f English (Rare) |
| DORIKA f Hungarian |
| DORIN m Romanian |
| DORINA (1) f Romanian |
| DORINA (2) f Hungarian |
| DORINDA f English |
| DORINE f English |
| DORIT (2) f Danish |
| DORITA f English (Rare), Spanish |
| DOROFEI m Russian |
| DOROFEY m Russian |
| DOROTA f Polish, Czech, Slovak |
| DOROTEA f Italian, Spanish, Swedish, Finnish, Croatian |
| DOROTÉIA f Portuguese (Brazilian) |
| DOROTEIA f Portuguese |
| DOROTĖJA f Lithuanian |
| DOROTEJA f Slovene, Croatian, Serbian, Macedonian |
| DOROTHEA f German, Dutch, Danish, Norwegian, English, Late Greek |
| DOROTHÉE f French |
| DOROTHEOS m Greek, Late Greek |
| DOROTHEUS m Late Roman |
| DOROTHY f English |
| DOROTTYA f Hungarian |
| DORTE f Danish |
| DORTHA f English |
| DÖRTHE f Low German |
| DORTHE f Danish |
| DORTHY f English |
| DORY f English |
| DOSIA f Polish |
| DOT f English |
| DOTTIE f English |
| DOTTY f English |
| FADDEI m Russian |
| FADDEY m Russian |
| FEDIR m Ukrainian |
| FEDOR m Russian |
| FEDORA f Russian |
| FEDYA m Russian |
| FEODOR m Russian |
| FEODORA f Russian |
| FYODOR m Russian |
| ISADOR m English (Rare) |
| ISADORA f English |
| ISADORE m English |
| ISET f Egyptian Mythology |
| ISIDOR m German, Russian, Macedonian |
| ISIDORA f Serbian, Macedonian, Spanish, Portuguese, Russian (Rare), Italian (Rare), English (Rare), Ancient Greek |
| ISIDORE m English, French, Georgian, Jewish |
| ISIDORO m Spanish, Italian |
| ISIDOROS m Ancient Greek |
| ISIDORUS m Late Roman |
| ISIDRO m Spanish |
| ISIS f Egyptian Mythology (Hellenized) |
| ISSY m & f English |
| IZIDOR m Slovene |
| IZIDÓRA f Hungarian |
| IZYDOR m Polish |
| IZZY m & f English |
| TAD m English |
| TADDEO m Italian |
| TADEÁŠ m Czech, Slovak |
| TADEJ m Slovene |
| TADEO m Spanish |
| TADEU m Portuguese |
| TADEUSZ m Polish |
| TADIJA m Croatian |
| TEA f Swedish, Danish, Norwegian, Finnish, Slovene, Croatian |
| TED m English |
| TEDDY m English |
| TEIJA f Finnish |
| TEJA f Slovene |
| TÉO m Portuguese |
| TEO m Italian, Spanish, Croatian |
| TEODOR m Swedish, Norwegian, Danish, Romanian, Czech, Slovak, Polish, Serbian, Croatian, Slovene, Hungarian, Bulgarian, Macedonian |
| TEODÓRA f Hungarian |
| TEODORA f Italian, Spanish, Portuguese, Swedish, Romanian, Polish, Bulgarian, Macedonian, Serbian |
| TEODORO m Italian, Spanish, Portuguese |
| TEODORS m Latvian |
| TEUVO m Finnish |
| TEWODROS m Eastern African, Amharic |
| THAD m English |
| THADDAEUS m Biblical |
| THADDAIOS m Biblical Greek |
| THADDEUS m English, Biblical, Biblical Latin |
| THEA f German, Swedish, Danish, Norwegian, English |
| THEDA f German |
| THEI m Limburgish |
| THEIRN m French |
| THÉO m French |
| THEO m English, Dutch |
| THEODOOR m Dutch |
| THEODOR m German, Swedish, Norwegian, Danish, Czech, Romanian |
| THEODORA f English, Greek, Ancient Greek |
| THÉODORE m French |
| THEODORE m English |
| THEODOROS m Greek, Ancient Greek |
| THEODORUS m Ancient Greek (Latinized), Dutch |
| TIIA f Finnish |
| TIVADAR m Hungarian |
| TÓDOR m Hungarian |
| TODOR m Bulgarian, Serbian, Macedonian |
| TODORKA f Bulgarian, Macedonian |
| TOŠE m Macedonian |
| TOSHE m Macedonian |
| TUDOR (2) m Romanian |
| URTĖ f Lithuanian |
