- Taalen by Aidan Grey (28 features)
- Tadiraki Language by CivilixXXX (45 features)
- Taiwazaiho by Ave94 (93 features)
- Tajju-njo Gwa by omniumfemina (67 features)
- Tajre by tapeworm (0 features)
- Talbas by chridd (36 features)
- Tallfellow by Enrique Gamez (142 features)
- Talmit by Roman Rausch (112 features)
- Talossan by R. Ben Madison (0 features)
- Tama by penguinsquishy (19 features)
- Tamma by willm (99 features)
- Tanaman by Jacob Norlund (16 features)
- Tangachi by dhagrow (141 features)
- Taraitola by Feaelin (3 features)
- Taruven by kaleissin (137 features)
- Tasza by Becca (86 features)
- Tatari Faran by H. S. Teoh (100 features)
- Ta Ti by Marq Thompson (59 features)
- Tauro-Piscean by S.C. Anderson (22 features)
- TBD by Kiriyow (94 features)
- Tedil Tamal by Violet Ascher (18 features)
- Telim by Irkan (49 features)
- Temarp by xroox (105 features)
- Temporary1 by Brv (104 features)
- Tengan by anders_ (67 features)
- Terpish by Eddy1701 (83 features)
- Tersales by Afsin Kum (109 features)
- Testarossa by T. E. Starossa (4 features)
- Testonian by spikedee (36 features)
- Thalurmian by Me (15 features)
- Thangi by NT (11 features)
- Tharingûl by Aldarantár Ornë (0 features)
- Thȧtareni by Manofzelego (55 features)
- Theadish by Kenner Gordon (35 features)
- the I-Picked-Some-Random-Features-With-a-Die Language) by Xing (140 features)
- Thensarian by IlL (141 features)
- Thiuas by shumai (137 features)
- Thosk by Dean Easton (53 features)
- Thulean by Rhebeqah (139 features)
- Thuun by january (133 features)
- TIAL by Jeffrey S. Jones (138 features)
- Tim Ar by Linguifex (27 features)
- Timuka by lgnjms (19 features)
- Tínaaqhe by leanancailin (107 features)
- Tine by xroox (111 features)
- Tinzirean by Ah Puch (123 features)
- Tircunan by Henrik Theiling (127 features)
- Tirelat by Herman Miller (96 features)
- Tizian by IlL (143 features)
- Tlar Canà by Linguifex (13 features)
- Tlaymyts by panglossa (138 features)
- Tmaśareʔ by Jan Strasser (134 features)
- Tnaaq by Xroox (124 features)
- Toaq by Hoemaı (135 features)
- Toilan by Jeffrey S. Jones (106 features)
- Tojin Simplified by Tookiekat (22 features)
- toka na musume by k1234567890y (127 features)
- Toki Ma by Shevek Urrasti (137 features)
- Toki Pona by Sonja Lang (139 features)
- Tolsian by Tètdeupö D'Yaoûrt Pérrimé (28 features)
- Tolvian by iewi (43 features)
- Toma Heylm by Amanda Furrow (15 features)
- Toníntaíjo Tóxe by MIRDAS (137 features)
- Torain by Matthew Turnbull (103 features)
- Torete by ekobor (29 features)
- Torimish by aarginost (105 features)
- Touijab Kikxot by Mythoswyrm (81 features)
- Town Speech by k1234567890y (124 features)
- Tranzydja by Becci Cat (0 features)
- Traup by xroox (142 features)
- Traxvus by Udrihel (39 features)
- Trayks by Joersk (132 features)
- Treyll by Heylola2 (34 features)
- Tribuggese by arrayfish (63 features)
- Trikuharric by Lachlan (58 features)
- Tsasa by Daniel Parker (0 features)
- Tsatsar by Daniel Parker (34 features)
- Tseeyo by wycoval (84 features)
- Tseltsolian by Piotr Gepfert (96 features)
- Tslure Thujekatsoth by Creyeditor (108 features)
- Tsols Oswahe by Linguifex (18 features)
- Tsolyani by M.A.R. Barker (92 features)
- Tšrând by Ben Felix (0 features)
- Tumbian by Xroox (90 features)
- Tvern El by A Walker Scott (28 features)